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USGS Activities Related to Environmental Health
Full listing of USGS activities related to Environmental health from the GeoHealth Newsletter
Summer 2010
Coal Combustion and Respiratory Health in the Navajo NationFirst Systematic Study of the Likely Impacts of Coal Combustion on Respiratory Health in the Shiprock, New Mexico, Area of the Navajo Nation
In collaboration with U.S. Geological Survey (USGS) scientists, Dine' College investigators surveyed 130 homes in the Navajo Nation near Shiprock, New Mexico, and found that one-quarter of those homes had stoves not originally designed for burning coal. The scientists concluded that residents of Shiprock and nearby communities appear to be at greater risk for respiratory disease than people in other communities on the Navajo Reservation based on a concurrent analysis of the geographic location of homes; household risk factors such as fuel, stove type, and use; the composition of locally used coal; and hundreds of thousands of hospital records. They additionally measured and chemically characterized fine particulate matter found in the air inside twenty homes. There are two large coal-fired power plants near Shiprock, with a third in the planning stages. While there is a large body of peer-reviewed literature that correlates coal-fired power plant proximity with risk of respiratory (and cardiovascular) disease, the main focus of this study was not on ambient air quality. Results from this study suggest that the risk could be reduced by making relatively simple and inexpensive changes to home heating methods, such as changing indoor home heating behavior and improving stove quality. More Information
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Contaminants in Groundwater Used for Public Supply
More than 20 percent of untreated water samples from 932 public wells across the United States contained at least one contaminant at levels of potential human-health concern, according to a recent study by USGS scientists. About 105 million people in the United States—more than one-third of the Nation’s population—receive their drinking water from about 140,000 public water systems that use groundwater as their source. Although the quality of finished drinking water (after treatment and before distribution) from these public water systems is regulated by the U.S. Environmental Protection Agency under the Safe Drinking Water Act, long-term protection and management of groundwater, a vital source of drinking water, requires an understanding of the occurrence of contaminants in untreated source water. Most (279) of the contaminants analyzed in this study are not federally regulated in finished drinking water under the Safe Drinking Water Act. In this study by the USGS's National Water Quality Assessment Program, water-quality conditions were assessed in source (untreated) groundwater from 932 public-supply wells, and in source and finished water from a subset of 94 wells. The samples were analyzed for as many as 6 water-quality properties and 337 chemical contaminants, including nutrients, radionuclides, trace elements, pesticides, volatile organic compounds, personal-care and domestic-use products, and manufacturing additives. This study evaluated the occurrence of contaminants in source water from public wells and their potential significance to human health, whether contaminants that occur in source water also occur in finished water after treatment, and the occurrence and characteristics of contaminant mixtures. Contaminants usually co-occurred with other contaminants. This study identifies which contaminant mixtures may be of most concern in groundwater used for public-water supply and can help human-health scientists to target and prioritize toxicity assessments of contaminant mixtures. More Information
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Future Recreational Water-Quality Nowcast for Pennsylvania's Presque Isle State Park
Presque Isle State Park, near Erie, Pennsylvania, is set to join many other beaches in the Great Lakes region where near real-time information is used to "nowcast" water-quality conditions for recreational waters. A nowcast of recreational water quality is much like a weather forecast except it estimates current conditions rather than future conditions. USGS scientists and their partners plan to develop a web-based nowcast system that will estimate current bacteria levels in the water of the Park's beaches to determine if recreational water-quality standards will be exceeded making the water unsafe to swim in. If succcessful, the nowcast system will be used by beach managers to determine if beach advisories or closings need to be posted to alert the public. A nowcast will prove useful because assessments of recreational water quality will be done in about an hour instead of the old method of assessment that takes about 24 hours. Scientists are now collecting background data on factors such as wave height, turbidity, number of birds on the beach, lake-current direction, rainfall, and wind direction—all are factors that could help predict bacteria concentrations. Funding from the Great Lakes Restoration Initiative helped make this work possible. More Information
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Fish Mercury Concentrations Decreased Rapidly in the 1970s and 80s
A recent USGS study examined a compilation of state and federal fish-monitoring data for trends in mercury levels in fish in U.S. rivers and lakes from 1969 to 2005. Results showed that 22 of 50 sites sampled across the Nation from 1969 to 1987 showed significant decreases in fish mercury concentrations, whereas only four sites showed increases. Mercury concentrations in fish decreased rapidly in the 1970s and more gradually or not at all during the 1980s. More recently, few changes were observed in fish mercury concentrations from 1996 through 2005. Upward mercury trends in fish occurred in the Southeast. Upward mercury trends in fish in the Southeast were associated with increases in wet mercury deposition measured in the National Mercury Deposition Network in that region. More Information
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Ayotte Receives Environmental Merit AwardUSGS Scientist Joseph D. Ayotte Received an Individual Environmental Merit Award from the U.S. Environmental Protection Agency for Work on Predicting Arsenic Occurrence in GroundwaterOn the 40th anniversary of Earth Day—April 22, 2010—the U.S. Environmental Protection Agency presented USGS Scientist Joseph D. Ayotte with an Individual Environmental Merit Award. Ayotte and his colleagues at the USGS's New Hampshire/Vermont Water Science Center created tools to help regulators better predict arsenic occurrence in groundwater and better understand the correlation between public health and arsenic, one of the most common contaminants found in New England groundwater. Research by Ayotte and his colleagues also allows regulators to understand the correlations between geology and arsenic. Other arsenic investigations in New England have used Ayotte’s work as a foundation for their own. More Information
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Arsenic and Dust: A Detective Story
USGS scientist Suzette Morman's research on arsenic in airborne dusts was published in the June 2010 Issue of Earth Magazine. The article "Arsenic: A Detective Story in Dusts" provides an overview of Morman's research in collaboration with other USGS scientists on the bioaccessibility of arsenic and other toxic metals in African airborne dusts transported to the Caribbean and southeastern United States. Morman’s interest in bioaccessible or soluble metals in geogenic dusts began with her collaboration with USGS scientist Richard L. Reynolds and his team, who conducts research on the conditions and factors that promote or suppress dust emission, with a focus on geologic, ecologic, hydrologic, and climatic processes as well as human activities. More Information |
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Satellite Tracking Reveals How Wild Birds May Spread Avian Flu
For the first time, migratory birds marked with satellite transmitters were tracked during an outbreak of highly pathogenic H5N1 avian influenza virus (H5N1) in Asia, providing evidence that wild birds may be partly responsible for the spread of the virus to new areas. Scientists from the USGS Alaska Science Center and the University of Tokyo attached satellite transmitters to 92 northern pintail ducks several months before the H5N1 virus was discovered in dead and dying whooper swans at several wetlands in Japan. They found that 12 percent of marked pintails used the same wetlands as infected swans and that pintails were present at those sites on dates the virus was discovered in swans. The scientists' work does not prove the marked pintails were actually infected with the H5N1 virus or that they definitively contributed to its spread. However, it does demonstrate that pintails satisfied two requirements necessary for migratory birds to spread the virus: they used outbreak sites at times when the virus was present, and some birds migrated long distances within a week of using the sites. Although the highly pathogenic H5N1 virus has not been discovered in North America, it continues to plague the poultry industry throughout Eastern Europe, Asia, and Africa and is a serious health threat to humans. More Information
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Effects of Plague on Wildlife May Have Been Underestimated in the Past
New results from USGS scientists and their colleagues show that the effects of plague on wildlife may have been underestimated in the past. Plague, a flea-borne bacterial disease, spreads rapidly, causing devastating effects to wildlife and posing risks to human health. Conservation and recovery efforts for imperiled species such as the black-footed ferret and Utah prairie dog are greatly hampered by the effects of plague. The scientists have demonstrated that plague continues to affect the black-footed ferret, one of the most critically endangered mammals in North America, as well as several species of prairie dogs, including the federally threatened Utah prairie dog—even when the disease does not erupt into epidemic form. "The impacts of plague on mammal populations remain unknown for all but a few species, but the impact on those species we have studied raises alarms as well as important questions about how plague might be affecting conservation efforts in general," said Dean Biggins, a USGS wildlife biologist. More Information
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How Do Contaminants Reach Public-Supply Wells?New USGS Groundwater Studies Explain What, When, and How Contaminants May Reach Public-Supply Wells Used for Drinking Water
Differences in the chemistry of the groundwater, the age of groundwater, and flow paths within aquifer systems can explain why all wells are not equally vulnerable to contamination. That's the results of several USGS studies on groundwater contamination across the Nation. USGS scientists tracked the movement of contaminants in groundwater and in public-supply wells in four aquifers in California, Connecticut, Nebraska, and Florida. They found that the importance of factors such as groundwater age and flow paths differs among the various aquifer settings. The findings in the four different aquifer systems can be applied to similar aquifer settings and wells throughout the Nation. "Our findings can help public-supply well managers protect drinking water sources by prioritizing their monitoring programs and improving decisions related to land use planning, well modifications, or changes in pumping scenarios that might help to reduce movement of contaminants to wells," said USGS scientist Sandra Eberts. More Information
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New Fact SheetUSGS Releases a New Fact Sheet on How USGS Science Serves Public HealthThe USGS is a source of natural science information vital for understanding the quantity and quality of our earth and living resources. This new fact sheet summarizes the USGS's role in providing the natural science information needed by health researchers, policy makers, and the public to safeguard public health. Buxton, H.T., 2010, USGS science serves public health: U.S. Geological Survey Fact Sheet 2010-3004, 2 p. |
Winter 2009/2010
Is the Dust in My House Toxic?Contaminated House Dust Linked to Parking Lots with Coal Tar Sealant
USGS scientists found that house dust in apartments with coal-tar sealcoated parking lots contained concentrations of polycyclic aromatic hydrocarbons (PAHs) that were 25 times higher than in house dust from apartments with other types of parking lot surfaces. Several PAHs are classified as probable cancer-causing agents. USGS scientists analyzed house dust from 23 ground-floor apartments in Austin, Texas. Half of the apartments had parking lots treated with coal-tar-based sealcoat. Small particles of the coal-tar-based sealcoat, which contain high concentrations of PAHs, could be tracked indoors by residents after they walk across the parking lot. Coal tar is a byproduct of the coking of coal, and can contain 50 percent or more PAHs by weight. Coal-tar-based pavement sealants have higher levels of PAHs compared to other sealants and other local contributors to the dust, including soot, vehicle emissions, and used motor oil. USGS is also actively investigating the occurrence of other potentially toxic compounds in household dusts, including polybrominated diphenyl ethers (PBDEs). More Information
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United States and Canada Discuss New Groundwater Arsenic Study
USGS scientists and their Canadian counterparts are considering the posiblity of conducting a collaborative study to develop tools to predict the probability of elevated levels of arsenic in groundwater in the eastern United States and Canada. In many areas of New England and Atlantic Canada, the groundwater concentrations of arsenic are above levels considered safe for human consumption. This is a concern because a significant portion of the population in these areas uses groundwater as their source of drinking water, and many households have domestic wells that are not tested periodically, as are community supply wells. The team of USGS and Canadian scientists seek to (1) coordinate North American soil and sediment sampling, (2) develop cross-border data sets for analysis of arsenic and other potential contaminants, (3) identify potential factors that can be used to predict the occurrence of arsenic, and (4) coordinate the research of scientists in the United States and Canada working on this environmental and health issue. The proposed predictive tools will help water resource managers on both sides of the border develop sound policies regarding human health and the occurrence of arsenic in groundwater. More Information
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Can Dust from Africa Make You Sick?Over the past few decades, increasing quantities of African dust have blown across the Atlantic Ocean to the Caribbean and the Americas. During that time, the dust’s composition has changed. USGS scientists have sampled dust in air in Africa and the Caribbean, and tested the dust for persistent organic contaminants and metals. These potentially toxic contaminants can originate from the burning of plastics, plant materials, animal waste, and human waste; from the widespread use of pesticides, plastics, and pharmaceuticals; and from increased industrialization. Multiple pesticides and other contaminants, including carcinogens, suppressors of immune systems, endocrine disruptors, and nervous system or liver toxins were identified from all sample sites. All are known to persist in the environment, accumulate in organisms, and are toxic at very low concentrations.
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From Drain Water to Drinking Water
Lake Mead serves as the primary drinking water source for Las Vegas, Nevada, and surrounding communities. Besides snowmelt from the Rockies, water levels are supplemented by the discharge of treated wastewater from communities along the Colorado River, including Las Vegas. This "use-reuse" practice is becoming commonplace in the arid Southwest and begs the question: "Are organic contaminants in our wastewaters ending up in our drinking water?" USGS scientists conducted studies using passive sampling devices ( semipermeable membrane device (SPMD) and polar organic chemical integrative sampler (POCIS) [pdf]) to track the occurrence of organic wastewater contaminants (including pharmaceuticals and personal care products, pesticides, and industrial chemicals) at sites in Las Vegas Wash (which carries treated wastewater from sewage treatment plants into Lake Mead). Samplers were also placed in the lake near Hemingway Harbor, and in tap water within the City of Las Vegas. Numerous chemicals including wood preservatives, plasticizers, pharmaceuticals, fragrances, and flame retardants were detected in the treated wastewater. The concentrations of these chemicals decreased as the wastewater entered Lake Mead due to removal by processes like dilution by the lake water and sorption to the bed sediments. A few of the flame retardants and pesticides also were detected in the drinking water, albeit at very low concentrations (nanogram per liter levels). A screen for hormonally active chemicals, such as those suspected to interfere with reproductive systems in fish, was used to test samples from each site. This screen indicated the potential for an estrogenic response in fish exposed to the wastewater in Las Vegas Wash; however, no potential response was detected in the samples from Lake Mead at Hemingway Harbor or in the finished drinking water samples. Little is know about the potential health effects of being exposed to the chemicals detected in drinking water. More Information
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Quality of Water Sources for Community Water Systems in the United States
In 2002, the National Water-Quality Assessment (NAWQA) Program of the USGS implemented the Source Water-Quality Assessment (SWQA) Program to characterize the quality of selected rivers and aquifers used as a source of supply to community water systems in the United States. Findings from 9 surface-water and 15 groundwater studies have been published. However, more studies have been completed and as many as 20 surface-water and 30 groundwater studies are planned to be completed by 2013. The primary objective of assessments is to determine the occurrence of about 280 primarily unregulated anthropogenic organic compounds in source water used by community water systems. Source water is the raw (ambient) water collected at a supply well or surface-water intake prior to water treatment used to produce finished water. A secondary objective is to understand occurrence patterns in source water and determine if these patterns also occur in finished water prior to distribution. The assessments are intended to complement drinking water monitoring required by Federal, State, and local programs, which focus primarily on post-treatment compliance monitoring. More Information
Recent SWQA Program PublicationsBanks, W.S.L., and Reyes, B., 2009, Anthropogenic organic compounds in source and finished groundwater of community water systems in the Piedmont Physiographic Province, Potomac River Basin, Maryland and Virginia, 2003-2004: U.S. Geological Survey Scientific Investigations Report 2009-5064, 33 p. Brown, C.J., and Trombley, T.J., 2009, Organic compounds in Running Gutter Brook water used for public supply near Hatfield, Massachusetts, 2003-05: U.S. Geological Survey Fact Sheet 2009-3076, 6 p. Carpenter, K., and McGhee, G., 2009, Organic compounds in Clackamas River water used for public supply near Portland, Oregon, 2003-05: U.S. Geological Survey Fact Sheet 2009-3030, 6 p. Ging, P.B., Delzer, G.C., and Hamilton, P.A., 2009, Organic compounds in Elm Fork Trinity River water used for public supply near Carrollton, Texas, 2002-05: U.S. Geological Survey Fact Sheet 2009-3090, 6 p. Hopple, J.A., Delzer, G.C., and Kingsbury, J.A., 2009, Anthropogenic organic compounds in source water of selected community water systems that use groundwater, 2002-05: U.S. Geological Survey Scientific Investigations Report 2009-5200, 74 p. Thomas, K.A., 2009, Organic compounds in Truckee River water used for public supply near Reno, Nevada, 2002-05: U.S. Geological Survey Fact Sheet 2009-3100, 6 p. |
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Can Geoscientists Help Understand Disasters?The answer is an unequivocal yes! After disaster strikes, many types of expertise are needed to understand the environmental health effects of the disaster and how best to respond to similar disasters in the future. The role of the geoscientist and USGS in general is the subject of a recent article in American Geological Institute's magazine Earth. The article, entitled "Report from Ground Zero: How Geoscientists Aid in the Aftermath of Environmental Disasters," recounts the efforts of a team of USGS scientists to help public officials understand the potential health and environmental implications of disasters and the ensuing rescue, recovery, and cleanup efforts. Since 2001, the team and their collaborators have responded to a number of disasters including:
Earth scientists have an important role to play in the aftermath of disasters that involves working with a wide range of partners, such as emergency responders, public health professionals, environmental cleanup managers, and others. Earth scientists can help these partners understand the environmental contamination that results from disasters, the extent and behavior of contamination in the environment, and the potential health risk to emergency responders and the public as they return to their homes. More Information |
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Pesticide Levels Decline in Corn Belt Rivers
USGS scientists find that concentrations of several major pesticides mostly declined or stayed the same in rivers and streams throughout the Nation’s Corn Belt from 1996 to 2006. The declines in pesticide concentrations closely followed declines in their annual application rates, indicating that reducing pesticide use is an effective and reliable strategy for reducing pesticide contamination in rivers. Scientists studied 11 herbicides and insecticides frequently detected in the Corn Belt region, which generally includes Illinois, Indiana, Iowa, Nebraska and Ohio, as well as parts of adjoining states. The commonly used herbicides cyanazine, alachlor, and metolachlor and the insecticide diazinon were included in the 11 herbicides and insecticides studied. The Corn Belt has among the highest rates of pesticide use in the Nation — mostly herbicides used for weed control in corn and soybeans. As a result, these pesticides are widespread in the region’s rivers and streams, largely resulting from runoff from cropland and urban areas. Elevated concentrations can affect aquatic organisms in streams as well as the quality of drinking water in some high-use areas where surface water is used for municipal supply. The USGS works closely with the U.S. Environmental Protection Agency, which uses USGS findings on pesticide trends to track the effectiveness of changes in pesticide regulations and use. More Information
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Planning for a Fun and Healthy Day at the Beach
Playing in the sand is a big part of a fun day at the beach. After digging in beach sand and making sand castles, however, washing your hands could greatly reduce your risk of ingesting bacteria that could make you sick. USGS scientists have determined that, although beach sand is a potential source of bacteria and viruses, hand washing may effectively reduce exposure to microbes that cause gastrointestinal illnesses. "Our mothers were right! Cleaning our hands before eating really works, especially after handling sand at the beach," said Dr. Richard Whitman, the lead scientist of the study. "Simply rinsing hands may help reduce risk, but a good scrubbing is the best way to avoid illness." The scientists measured how many Escherichia coli (E. coli) bacteria could be transferred to people’s hands when they dug in sand, and they analyzed sand from the shores of Lake Michigan in Chicago. Using past findings on illness rates, the scientists found that if individuals were to ingest all of the sand and the associated microbial community retained on their fingertips alone, 11 individuals in 1,000 would develop symptoms of gastrointestinal illness. More Information
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Vaccines Protect Prairie Dogs Against Plague
A new oral vaccine is showing significant promise in the laboratory as a way to protect prairie dogs against sylvatic plague. It may eventually protect endangered black-footed ferrets who now get the disease by eating infected prairie dogs. Black-footed ferrets are one of the rarest mammals in North America. Sylvatic plague is an infectious bacterial disease usually transmitted from animal to animal by fleas. This exotic disease is usually deadly for black-footed ferrets and their primary prey, prairie dogs, resulting in local extinctions or regional population reductions. Along with other wild rodents, prairie dogs are also considered a significant source of plague for other wildlife, domestic animals, and people in the western United States. An oral vaccine could be put into bait and delivered into the field without having to handle any animals; handling is a process that is time-consuming, costly, and sometimes stressful for the animals. Prevention of plague in wild rodents by immunization could reduce outbreaks of the disease in animals, thereby reducing the risk for human exposure to the disease. More Information
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Engaging the Public-Health Education Community
The increasing complexity of today's public health issues requires a multidisciplinary approach that includes broad expertise in the earth and environmental sciences. Two USGS scientists are engaging the public-health community with cross-discipline course offerings at universities. USGS geologist Geoffrey Plumlee is co-teaching a class at the University of Colorado School of Public Health (UCSPH) titled "Environmental Health from the Ground Up: Exploring Natural and Manmade Disasters." Co-taught with an industrial hygienist and a pulmonary physician, the course provides a unique integration of the earth sciences, exposure sciences, and medical sciences. The course's instructors present various recent disasters to illustrate fundamental concepts of environmental and occupational health. Plumlee's participation has highlighted a broad spectrum of USGS work on natural sciences and health to the public health community, including USGS work on the World Trade Center, asbestos, hurricane Katrina, volcanic eruptions, wildfires, and mining-related environmental health issues.
As part of George Mason University's Geographic Information Systems (GIS) certificate program, USGS geographer Lee De Cola is teaching a three-day class on analysis of environmental and public health issues using GIS entitled Public Health & Analysis. The course teaches how to use GIS both to manage and visualize data about environmental quality and biological resources; and to analyze complex interactions that affect the health of organisms within regions. Methods such as multivariate mapping, interpolation and forecasting, as well as such key concepts of epidemiology as cluster detection, transmission, and incidence are covered in the course. More Information
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Summer 2009
The USGS Studies Sand Fly-Borne Leishmaniasis Disease in Tunisia
USGS scientist Dr. Howard S. Ginsberg is participating in a study of the transmission and prevention of the disease Zoonotic Cutaneous Leishmaniasis (ZCL) in Tunisia. Diseases that are transmitted from animals to humans are called zoonotic diseases. Leishmaniasis is caused by several pathogenic species of single celled parasites in the genus Leishmania. In this case, Leishmania major is transmitted to humans by a sand fly (Phlebotomus papatasi), which is common in many parts of Africa. The pathogen is carried by rodents, notably sand rats (Psammomys obesus), and jirds (Meriones shawi). ZCL causes severe skin lesions, which generally take months to heal, and sometimes leave disfiguring scars. Leishmaniasis is primarily a disease of children, with thousands of cases per year in Tunisia. Dr. Ginsberg was invited to work on this problem by scientists at the Pasteur Institute in Tunis (Institut Pasteur de Tunis). The research group at the Pasteur Institute (led by Dr. Elyes Zhioua) has developed a potential approach to managing the disease. The approach involves establishing rabbit holes near the homes of farming families in central Tunisia where the infection is most prevalent. Their work suggests that rabbit holes could deflect the sand flies from entering houses, lowering the number of flies that might potentially bite people. Dr. Ginsberg is working with the research group at the Pasteur Institute on a comprehensive study of sand fly movement patterns and Leishmania major transmission dynamics to determine whether their approach will work on a large scale. More Information
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Is Methylmercury in Pacific Ocean Fish of Human Origin?
Given the obvious importance of marine food webs to human methylmercury exposure, it is remarkable that scientists are still wondering: where do fish, such as Pacific Ocean tuna, acquire their methylmercury? A U.S. Geological Survey (USGS) scientist and his university colleagues have discovered that bacteria in ocean water convert elemental mercury from atmospheric deposition to methylmercury when the bacteria degrade the remains of dead phytoplankton that “rain” down to ocean mid-depths. Before this work, some scientists hypothesized that methylmercury in the open ocean was geologic in origin and associated with deep-sea spreading centers. The results from these scientists' work do not support the geologic origin hypothesis. Consumption of ocean fish and shellfish account for over 90 percent of human methylmercury exposure in the United States, and tuna harvested in the Pacific Ocean account for 40 percent of this total exposure. Currently, national and international groups are seeking the most effective ways to minimize human methylmercury exposure, and the scientists' article in Global Biogeochemical Cycles presents the first evidence linking current atmospheric mercury deposition to methylmercury in Pacific Ocean fish. Environmental professionals, regulators, resource managers, and other decision makers can use these results to help make informed decisions about atmospheric mercury emissions and potential human exposure to methylmercury from fish consumption. More Information
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Studying Avian Influenza: Tracking Wild Birds in India and Hong Kong
USGS experts in satellite telemetry are helping track the movements of wild waterfowl in support of surveillance programs in countries with avian influenza outbreaks. Waterfowl were captured during December 2008 in Hong Kong at the Mai Po Nature Reserve and in Orissa, India, at Koonthankulum Sanctuary, Tamil Nadu, and Chilika Lagoon. The waterfowl were outfitted with miniaturized global positioning system (GPS) transmitters. The transmitters allow USGS scientists to track birds to help the scientists understand whether relationships exist between the locations of these marked birds and avian influenza outbreaks along the birds’ migratory pathways. The USGS is working with the United Nations Food and Agriculture Organization, government agencies, and non-governmental organizations in this effort. This collaborative effort will provide insights into the movement of avian influenza viruses and other diseases in East Asian flyways, improve the knowledge base on the ecological habits of waterfowl internationally, and enhance health professionals' understanding of the interactions among wild and domestic birds.
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Contaminants in 20 Percent of U.S. Domestic Wells
More than 20 percent of private domestic wells sampled across the United States contain at least one contaminant at levels of potential health concern. Fifteen percent of the Nation's population - about 43 million people - use drinking water from private wells, which are not regulated by the Federal Safe Drinking Water Act. USGS scientists sampled about 2,100 private wells in 48 States and found that the contaminants most frequently measured at concentrations of potential health concern were inorganic contaminants, including radon and arsenic. These contaminants are mostly derived from the natural geologic materials that make up the aquifers from which well water is drawn. Manmade organic chemicals were detected in more than half of the sampled wells but seldom at concentrations of potential human-health concern. Concentrations were considered of potential human-health concern when they exceeded U.S. Environmental Protection Agency Maximum Contaminant Levels (MCLs) or calculated Health-Based Screening Levels. The wells were sampled prior to any in-home water treatment. More Information |
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Estrogen Exposure Linked to Lowered Immunity in Fish
USGS scientists have found that exposure to estrogen reduces the production of immune-related proteins in fish. This suggests that certain compounds, known as endocrine disruptors, may make fish more susceptible to disease. The study may provide new indications of why intersex fish (the presence of both male and female characteristics within the same fish), fish kills, and fish lesions often occur together in the Shenandoah and Potomac Rivers. The results of the study showed that large-mouth bass injected with estrogen produced lowered levels of hepcidin, an important iron-regulating hormone in mammals that is also found in fish and amphibians. This was the first published study demonstrating control of hepcidin by estrogen in any animal. Besides being an important iron-regulating hormone, the scientists also conjecture that hepcidin may act as an antimicrobial peptide in mammals, amphibians, and fish. Antimicrobial peptides are the first line of defense against disease-causing bacteria, fungi, and viruses in animals. More Information
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Mixed News on Mercury in Indiana’s Water
Rain and snow falling in Indiana contains less mercury than it did in years past. Yet some of the State's major waterways have mercury levels that could be harmful to humans and wildlife. State health officials advise people to limit their consumption of some fish caught in Indiana because of mercury contamination. USGS scientists demonstrated that mercury levels in the State vary from place to place, season to season, and year to year. According to their report on mercury in streams, nearly 6 percent of water samples collected from 2004 to 2006 had mercury levels that exceeded the Indiana water-quality standard established to protect human health. Mercury concentrations in 73 percent of the samples exceeded the more restrictive State water-quality standard protecting wildlife. More than 80 percent of the water samples had detectable methylmercury, the most toxic form of mercury that accumulates in fish, birds, and mammals at the top of food chains. The USGS, in cooperation with the Indiana Department of Environmental Management, has a long-term program to monitor mercury statewide, whereby mercury in precipitation is measured every week at five stations in Indiana and every season at 25 stream sites in the State's major watersheds. More Information |
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USGS Collaborating on a Study to Determine the Factors that Control the Geographic Distribution of Lyme Disease
The USGS is working on a large-scale study to determine the causes for the observed distribution of Lyme disease in the eastern United States. The disease-carrying deer tick, Ixodes scapularis, can be found throughout the eastern part of the country; while Lyme disease in humans is common in the northeast and northern Midwest states, it is rare in southern states. The USGS is collaborating on a National Science Foundation funded project with scientists from several universities (Michigan State University, University of Rhode Island, Hofstra University, Georgia Southern University, University of Tennessee, and University of Montreal). The research team is looking at patterns of vertebrate community structure, cyclic and seasonal tick behavior, and tick genetics in four regions of the United States (northeast, north central, southeast, and south central), to assess the contributions these factors might have on the transmission the Lyme bacterium, Borrelia burgdorferi. More Information |
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Invasive Fish Tilts the Mercury Scales
When the threadfin shad fish invaded California's Clear Lake, it shook up the food web by eating all the tiny animals, known as zooplankton [http://www.absc.usgs.gov/research/seabird_foragefish/marinehabitat/home.html#zooplankton], that many other small fish depend on for food. As a result, the resident small fish became more dependent upon bottom-dwelling prey such as the larvae of small flies called midges, which live in methylmercury contaminated sediments. Methylmercury is a very toxic form of mercury found in some aquatic ecosystems, and at high exposure levels, methylmercury can affect the nervous and reproductive systems of fish, wildlife, and humans. Thus, high levels of methylmercury in small fish may not only impact their health, but also increase the risk of exposure to animals higher in the food chain that eat them. USGS scientists found that during times of high shad abundance, total mercury concentrations in the resident fish increased by approximately 50 percent compared to when shad were not present in the lake. More Information
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HealthMap: Alerts on Global Wildlife and Human Diseases
HealthMap is a new tool providing alerts on human, domestic animal, and wildlife diseases throughout the world - and it's all on one map! Information comes from various news media and other sources, including the USGS wildlife disease news. This integrated approach of combining health information for wildlife, humans, and domestic animals supports the growing belief that examining their interrelationships may lead to new discoveries. HealthMap was created by Harvard-MIT and the Children's Hospital Informatics Program. More Information |
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Watershed Characteristics Determine How Much Atmospherically Deposited Mercury Ends Up in Fish
A recent published series of papers resulting from a USGS study on the fate of atmospherically deposited mercury in eight watersheds shows that some stream ecosystems are much more sensitive to atmospheric deposition of mercury than others. The results showed that total mercury and methylmercury concentrations in the streams were much more variable than the observed variation in the atmospheric deposition of mercury (9-fold for streams and 4-fold for atmospheric deposition). The characteristics of the watershed, particularly the abundance of wetlands and amount of natural organic carbon in stream water, are the primary determinants for how mercury is transported and bioaccumulated in stream food webs. The eight streams in the study were located in Oregon, Wisconsin, and Florida. Streams in urban areas (Portland, Oregon; Milwaukee, Wisconsin; and Orlando, Florida), and streams in relatively undeveloped areas in these States were included in the study. The findings from this study can help decision makers to better anticipate concentrations of mercury and methylmercury and how mercury makes its way into fish in unstudied streams in comparable environmental settings. More Information
ReferencesBrigham, M.E., Wentz, D.A., Aiken, G.R., and Krabbenhoft, D.P., 2009, Mercury cycling in stream ecosystems--1. Water column chemistry and transport: Environmental Science and Technology, v. 43, no. 8, p. 2,720-2,725, doi:10.1021/es802694n. (Free Download) Chasar, L.C., Scudder, B.C., Stewart, A.R., Bell, A.H., and Aiken, G.R., 2009, Mercury cycling in stream ecosystems--3. Trophic dynamics and methylmercury bioaccumulation: Environmental Science and Technology, v. 43, no. 8, p. 2,733-2,739, doi:10.1021/es8027567. (Free Download) Marvin-DiPasquale, M., Lutz, M.A., Brigham, M.E., Krabbenhoft, D.P., Aiken, G.R., Orem, W.H., and Hall, B.D., 2009, Mercury cycling in stream ecosystems--2. Benthic methylmercury production and bed sediment-pore water partitioning: Environmental Science and Technology, v. 43, no. 8, p. 2,726-2,732, doi:10.1021/es802698v. (Free Download) |
Winter 2008/2009
Plague Vaccine for Endangered Ferrets
The connection between plague in an endangered ferret and plague in humans might seem far-fetched, but scientists are increasingly concerned about diseases that can be transmitted between animals and humans. Scientists have known that the potential for transmission is likely especially when humans come into direct contact or are in close proximity with infected animals. Rats are the normal culprits, but the potential for transmission from wild animals is also likely. In November 2007 a National Park Service biologist contracted plague from a cougar and died. Sylvatic plague is a bacterial disease caused by Yersinia pestis and transmitted mostly by fleas. It afflicts many mammalian species, including humans. The endangered black-footed ferret is no exception. USGS scientists, in collaboration with colleagues at other federal agencies and the University of Wisconsin, are developing and testing vaccines that can be used to protect black-footed ferrets and their primary prey, prairie dogs, against plague. Sylvatic plague is usually deadly for both black-footed ferrets and prairie dogs. After success with captive animals, wildlife biologists have vaccinated ferrets and prairie dogs in an effort to control an outbreak of plague in the Conata Basin area of Buffalo Gap National Grasslands in southwestern South Dakota. This is the first time the vaccine has been used during a major plague epizootic (an animal version of a human epidemic). However, injectable vaccines are not practical for field use in free-ranging wild animals. Ultimately, management of the disease in ferrets will depend on managing the disease in prairie dogs. As one could imagine, immunizing entire populations of wild prairie dogs and other rodents is highly challenging, but preliminary studies indicate prairie dogs can be successfully immunized by distribution of vaccine-laden baits in the wild. These studies suggest that plague could be managed through oral immunization, which is good news. As residential areas encroach on plague outbreak or endemic areas, controlling plague in wildlife and tracking trends in plague transmission becomes more and more relevant to public health. More Information
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Genetics Studies Can be Useful During Bear Maulings Investigations
The news is full of stories about using DNA evidence to solve many types of crimes. USGS scientists have also shown that an adaptation of these same modern molecular genetic techniques can be applied to issues of public safety involving attacks by wild animals. Scientists from the USGS Alaska Science Center, Molecular Ecology Laboratory positively identified, through DNA analysis, that a bear killed by Alaska Department of Fish and Game (ADFG) was the same bear that attacked a runner on an Anchorage trail this past summer. The scientists analyzed samples collected from the runner's clothing and compared them with the bear's DNA and with DNA previously collected from over 20 brown bears in the Anchorage area. Genetic data obtained from the samples from the clothing were identical to the DNA extracted from the bear killed by ADFG. These results demonstrate the utility of applying DNA-based techniques to issues of public safety involving attacks by wild animals. More Information
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Low Levels of Man-Made Chemicals Found in Drinking Water
Low levels of certain man-made chemicals remain in public-water supplies after being treated in selected community water facilities. This is the finding of a USGS study of water from nine rivers used as a source of supply for public water systems and in drinking water after treatment. Most of the man-made chemicals assessed in the study are unregulated in drinking water and are not required to be monitored or removed. Scientists tested water samples for about 260 commonly used chemicals, including pesticides, solvents, gasoline hydrocarbons, personal care and household-use products, disinfection by-products, and manufacturing additives. Low levels of about 130 of the man-made chemicals were detected in rivers before treatment at the public water facilities. Nearly two-thirds of those chemicals were also detected after treatment. Concentrations of the detected compounds generally were less than one microgram per liter (1 µg/L). Safe drinking water supplies are important for maintaining and preserving public health. The results of this study and others like it will help water-resource managers develop sound policies and practices that help protect human health. More Information
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Genetics Provide Evidence for the Movement of Avian Influenza Viruses from Asia to North America via Migratory Birds
As part of a multi-agency research effort to understand the role of migratory birds in the transfer of avian influenza viruses between Asia and North America, USGS scientists and their colleagues at the U.S. Fish and Wildlife Service and the University of Tokyo have found genetic evidence supporting the role of migratory birds in the intercontinental transfer of influenza viruses. In an article published in Molecular Ecology, USGS scientists reported that nearly half of the low pathogenic avian influenza viruses they found in wild northern pintail ducks in Alaska contained at least one (of eight) gene segments that were more closely related to Asian than to North American strains of avian influenza. USGS scientists, in collaboration with the U.S. Fish and Wildlife Service, Alaskan state agencies, and Alaskan native communities, obtained samples from more than 1,400 northern pintails from locations throughout Alaska. Samples containing viruses were then analyzed and compared to virus samples taken from other birds in Eastern Asia where northern pintails are known to winter and from North American waterfowl. Researchers chose northern pintails as the focus of the study because (1) they are known to migrate between North America and Asia, (2) they are fairly common in North America and Asia, and (3) they are frequently infected by low pathogenic avian influenza. None of the samples were found to contain completely Asian-origin viruses and none were highly pathogenic. These results demonstrate the advantage of applying genetic-based techniques to assess the global movement of diseases by wild animals.
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Are Pharmaceuticals in Feed Water to Drinking Water Facilities?
USGS scientists conducted the first national study of the occurrence of selected pharmaceuticals, personal-care products, detergents, flame retardants, naturally occurring sterols, and other chemicals of emerging environmental concern in untreated sources of drinking water in the United States. These emerging contaminants are commonly associated with animal and human waste waters. USGS scientists collected data from 49 surface-water intakes and 25 wells that would subsequently have been treated for drinking water. The samples were collected in 25 states and Puerto Rico. This study follows previous USGS research on emerging contaminants in susceptible ground water and surface water, that is, flowing from areas of high population density and/or high density of animal agriculture. The results of these studies will help water-resource managers, health professionals, scientists, and regulators determine if the concentrations and mixtures of chemicals found pose a threat to human or ecological health. More Information |
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Lead Shot and Sinkers: Weighty Implications for Ground-Water Quality and Ecological Health
Lead is a metal with no known beneficial role in biological systems, and its use in gasoline, paint, pesticides, and solder in food cans has nearly been eliminated. Although lead shot was banned for waterfowl hunting in 1991, its use in ammunition for upland hunting (typically hunting for small game—quail, pheasants, rabbits, —on dry land), shooting sports, and in fishing tackle remains common. USGS scientists and their colleagues authored a technical review published by The Wildlife Society concluding that significant amounts of lead are left behind in the environment from the use of lead shotgun pellets, bullets, and fishing tackle. At upland hunting sites, up to 400,000 shot per acre may be deposited annually. Individual shooting ranges may receive 1.5 to more than 16 tons of lead shot and bullets annually. Although lead from spent ammunition and lost fishing tackle is not readily released into the environment, given the right environmental conditions it can slowly dissolve in water. Scientists have found some cases of lead contamination in ground water near some shooting ranges and at heavily hunted sites, particularly those hunted year after year. The most significant hazard to wildlife is through direct ingestion of spent lead shot and bullets, lost fishing sinkers and tackle, and related fragments, or through consumption of wounded or dead prey containing lead shot, bullets, and/or fragments. This report provides useful information for resource managers to assess lead issues and to develop sound management policies. More Information
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A New Tool to Help Assess Environmental Human Health Threats Along the U.S.-Mexico Border
Dramatic urban growth, rapid industrialization, and infrastructure problems in cities along the border between the United States and Mexico have increase environmental problems and risks associated with human health. These stressors threaten the quality of life in the region and raise concerns about the interdependence of environmental sustainability and human health. To help environmental and public-health professionals of both nations USGS scientists are developing a tool that will provide easy access to environmental-quality data to aid in identifying human populations at risk. The map-based tool uses geospatial statistical techniques to analyze various indicators of environmental quality (water quality, soil geochemistry, land use, and other data) relative to measures of fish and human health. The tool is being developed as part to the USGS U.S.-Mexico Border Environmental Health Initiative (BEHI). BEHI is a multi-agency effort involving collaboration between Federal and local entities in both the U.S. and Mexico.
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Beach Sand Often More Contaminated than Water
Recent research has revealed that beach sand contains high concentrations of E. coli and other fecal indicator bacteria, often greatly exceeding the concentration in beach water. In many States beach water is routinely analyzed for E. coli and other fecal indicator bacteria to determine whether human sewage is present. When bacteria concentrations in water exceed a certain threshold, beaches are typically closed to swimming or swimming advisories are posted. For most beach closings, the reason for high bacteria concentrations remains unknown. However; there is growing evidence that beach closings due to elevated fecal indicator bacteria may be linked to bacteria in the sand. Bacteria are often present in high concentrations in beach sand independent of any recent contamination events. The health risk associated with these bacteria is as yet unknown, but preliminary studies are being conducted. This information will potentially help public-health and environmental professionals make informed decisions about the causes behind beach closings. More Information
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No Child Left Inside
Step away from the television! Turn off your computer! Head for the outdoors! The evidence is growing: Americans spend less and less time outdoors. During Earth Science Week 2008 the USGS encouraged everyone, especially young people, to get outside. USGS Earth Science Week Web site offered a few solutions, such as a list of parks with notes on interesting, exciting or unique things to do in each park, and downloadable 3-D National Parks map with instructions on how to create your own 3-D glasses! The USGS partnered with the American Geological Institute and its member societies to sponsor this annual international event. Earth Science Week 2009 is October 11-17. |
Summer 2008
Mosquitoes and West Nile Virus: Where are the Virus Carriers?
West Nile virus was not reported in the Western Hemisphere until an outbreak in the fall 1999. Since then, the virus has spread across the United States and Canada and south into Central America and the Caribbean. The U.S. Geological Survey (USGS) has been conducting a variety of research and assessment projects on the spread of West Nile virus. The following are a sample of three projects the USGS and its collaborators have recently conducted to answer questions about West Nile and other viruses.
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Birds Carrying Diseases: A Cross-Boundary Phenomenon?
What is the likelihood that a hunter will find a disease-carrying bird that came from another country? It's a possibility. A hunter in Mississippi recently found a pintail duck originally banded in Japan 8 years before. This finding shows the connectivity between the United States and Asia through migratory birds. Highly pathogenic avian influenza H5N1 has previously occurred in Japan, and scientists now have the opportunity to study whether the North American and Asian pintail populations are exchanging avian influenza viruses and whether it is possible for pintails to transmit these viruses from Japan to North America. More Information
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New Fact Sheet: Water Availability—The Connection Between Water Use and Quality
Competition for water is becoming more severe as the Nation's population continues to increase, which places greater demands on water resources. Water impaired by human activities puts limits on the use of available water. Perhaps less understood is that subtle human influence on the quality of our water can release naturally occurring contaminants, like uranium and radium, into streams and aquifers, thereby constraining the availability of usable water. A new fact sheet from the USGS is available that summarizes these issues in an easy to understand format. The fact sheet provides examples of how water use and management practices, together with natural features and the landscape, can affect water quality, and thus the availability of water for critical uses. More Information
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Beach Safety and Water Quality: A New Collaborative Project
A new collaborative project has begun to provide improved information on water quality to beach managers in the Great Lakes states. Beach managers are often faced with deciding whether to close beaches to protect public health. Project scientists are focusing on improving water-quality forecasting by enhancing and expanding models that help beach managers decide if beach advisories or closures are necessary. The project has been funded through interagency implementation of the President's Ocean Action Plan and will be a collaborative effort that will draw on the expertise of USGS and other Federal, State, and local agencies. More Information |
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Global Wildlife Disease News Map
In our globalized world, disease can spread in unprecedented time and space. However, keeping abreast of wildlife disease occurrences and trends can be challenging, despite the significant impact of those diseases on domestic animal and human health. The Wildlife Disease Information Node (WDIN) has added a new feature, the Global Wildlife Disease News Map. This unique online map makes it possible to follow the latest reports of nearly 50 diseases and other health conditions that threaten wildlife, domestic animal, and human health in a world wide context. The map works by displaying articles on the detection and spread of wildlife disease, as well as other conditions that affect the health of wildlife, based on their geographical location. The Map is populated by news stories compiled as a part of WDIN’s news services. The WDIN staff combs through a variety of news sources and combines disparate information about wildlife disease and other wildlife health-related topics into the Wildlife Disease News Digest. More Information |
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Pesticides in the Lower Clackamas River and in Samples of Drinking Water
USGS scientists studying the occurrence of pesticides in the lower Clackamas River watershed found a variety of pesticides in water samples from the lower Clackamas River and its tributaries. Samples were also collected from a drinking-water treatment plant that uses the river as a raw-water source. Trace-level detections of pesticides were found in treated drinking water from the plant. All of the detections in drinking water were, however, far below existing U.S. Environmental Protection Agency drinking-water standards and other human-health benchmarks. Fifteen pesticides were detected variously in 18 samples of the finished drinking water. The four most common pesticides detected were diuron, simazine, dacthal, and hexazinone, which occurred in two to four samples each. These low-level detections of pesticides can be used to inform water resource managers about their presence and gives some idea of their respective levels in source and finished drinking water, which will allow the managers to make informed decisions about the suitability of local water resources and its susceptibility to influence from human activities. The Clackamas County Department of Water Environment Services cooperated with the USGS on the study. More Information
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Ingredients in Common Household Products Found in Earthworms
Earthworms studied in agricultural fields where biosolids and manure were applied have been found to contain chemicals from household products and manure, indicating that such substances are entering the food chain. The chemicals investigated include a range of active ingredients in common household products such as detergents, antibacterial soaps, fragrances, and pharmaceuticals. More Information |
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Modeling the Probability of Arsenic in Ground Water in Pennsylvania: A Tool for Exposure Assessment
Detectable concentrations of arsenic have been reported in ground water from commercial, industrial, public, and private water-supply wells in Pennsylvania. USGS scientists and their collaborators have shown that ground water originating from marine or black shales and glacial sediments as well as ground water in the Newark Basin (a large sedimentary basin in eastern Pennsylvania and northern New Jersey) are enriched with arsenic in comparison to many other areas of Pennsylvania. Although the type of rock (lithology) is an important variable in understanding the occurrence of arsenic in ground water, other factors that may affect the fate and transport of arsenic in ground water include: the chemistry of ground water (pH, dissolved oxygen (DO), and oxidation/reduction potential (REDOX)), presence of iron sulfide minerals (such as pyrite, nitrate, and manganese), proximity to intrusive igneous rocks, resource extraction (oil and gas production), topographic setting, surface slope, soil characteristics, precipitation, land use classification, ground-water residence time, well yield, and well depth. To evaluate the many variables that affect arsenic in ground water, scientists from the USGS will develop a statistical model, known as a logistic-regression model, to estimate the probability that arsenic concentrations in wells will exceed a threshold value of 4 micrograms per liter (µg/L). The model will be designed to show areas or regions in Pennsylvania that have greater than average probability of containing ground water with elevated (greater than 4 µg/L) concentrations of arsenic. Water-resource managers and health professionals will be able to use the model along with other earth-science information to conduct exposure assessments as well as to develop sound policies and programs regarding arsenic in wells used for drinking water. The Pennsylvania Department of Health and the Pennsylvania Department of Environmental Protection provided funding for this project. For more information contact Dennis Low, USGS, New Cumberland, Pennsylvania. |
January 2008
Environmental and Health Hazard Characterization of Ash and Burned Soils from the October 2007 Southern California WildfiresFollowing the October 2007 firestorms in southern California, USGS scientists collected ash and soil samples from two residential areas as well as 26 other sites within burned areas. The areas included the Harris, Witch, Ammo, Santiago, Canyon and Grass Valley fires. The samples are being analyzed to identify characteristics of the ash and soils from both wildland and suburban burned areas that may adversely affect water quality, human health, endangered species and debris-flow or flooding hazards. Study leads are Geoff Plumlee (gplumlee@usgs.gov) and Deborah Martin (damartin@usgs.gov). Field sampling was carried out November 2-9 2007 by Todd Hoefen and Ray Kokaly, in collaboration with Robert Fisher, Eric Reichard, and other scientists from the San Diego office of the USGS California Water Science Center. Results to date indicate that ash from two residential areas burned by the Grass Valley and Harris wildfires contains very high levels of caustic alkali materials and can contain somewhat elevated levels of metals such as arsenic, lead, zinc and copper. Ash from burned wildlands can also contain caustic alkali materials and some metals, though generally at lower levels than the residential ash. These findings are consistent with the scientific knowledge about wildfire ash that have led numerous public health agencies to issue advisories regarding appropriate precautionary measures to avoid health problems associated with exposure to the ash by persons working in burned wildland areas or cleaning up burned residences. Such measures include, use of appropriate respiratory protection, gloves, long-sleeved shirts and long pants, dust mitigation measures, and washing of skin contacted by the ash. The study results also indicate that high-alkalinity rain-water runoff from both residential and wildland burned areas may adversely affect ecosystems and the quality of surface drinking water supplies. Preliminary results of the ash characterization studies were released to emergency responders in late November, 2007, and to the public the following week on December 4, 2007 via USGS Open-File Report 2007-1407. |
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Climate-Driven Ocean Changes Can Cause Harmful Algal Blooms (HABs) in Estuaries
A team of U.S. Geological Survey (USGS) scientists found that a cooling in ocean temperatures in the first half of this decade led to increased algal blooms in San Francisco Bay, California. Algal blooms can have adverse effects on the environment. Some types of algae produce toxins that can cause health problems and sometimes death to humans and wildlife. Some toxic or harmful algal blooms (HABs) discolor water and are commonly referred to as red tides. Linking the occurrence of algal blooms to changes in the ocean is a surprising result because the phytoplankton blooms are often associated with increases in the amount of nutrients, such as nitrogen and phosphorus, entering estuaries from such sources as wastewater treatment plants and runoff from agricultural fields. In this case, the increase in algal blooms in San Francisco Bay occurred during a period of decreasing nutrient concentrations and inputs. This result shows that nutrient enrichment is not the only cause of phytoplankton blooms in estuaries. Resource protection and management programs, for such resources as shellfish beds and recreational waters, could benefit from a wider geographic perspective that recognizes the coastal ocean as an important source of estuarine variability, and a longer time perspective that recognizes the importance of climate processes that fluctuate over periods of decades. More Information
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Institute of Medicine’s Climate Change and Infectious Disease Forum
On December 4 and 5, 2007, Dr. Leslie Dierauf (USGS National Wildlife Health Center Director), at the invitation of the National Academy of Sciences Institute of Medicine’s Forum on Microbial Threats, participated in a 2-day dialogue in Washington, DC, titled “Global Climate Change and Extreme Weather Events: Understanding the Potential Contributions to the Emergence, Reemergence and Spread of Infectious Disease.” The Institute of Medicine’s (IOM) Forum on Microbial Threats semi-annually provides structured opportunities in neutral settings for health professionals from both the private and public sectors (including physicians, veterinarians, public health specialists, agricultural scientists, environmental scientists, and others) to strengthen and forge networks and linkages by discussing current scientific and policy matters related to the prevention, detection, management, and research in the realm of infectious diseases. The meeting consisted of four major sessions -- Direct and Indirect Effects of Climate Change on Vector- and Non-Vector-Borne Diseases, Environmental Trends and Their Influences on Disease Emergence, Prediction and Intervention in Disease Outbreaks Related to Climate Change, and International Public Health and Foreign Policy Implications on the Spread of Infectious Diseases. The most enlightening part of each session during the 2-day dialogue, was the significant blocks of time devoted lively and extended discussions. More Information |
June 2007
Predicting Areas with Elevated Arsenic in Bedrock Wells in New Hampshire
New evidence suggests that bladder cancer mortality is correlated with private well use in the New England region. As part of a full-scale epidemiologic study of bladder cancer in northern New England, the U.S. Geological Survey in cooperation with the National Cancer Institute, Colorado State University, and Dartmouth School of Medicine developed a model that predicts which areas in New England are likely to have bedrock wells with drinking water with arsenic concentrations exceeding 5 micrograms per liter (µg/L). The USGS as started a new project in partnership with the New Hampshire Department of Human Health Services (NHDHHS), which is scheduled to begin later this year. The project will endeavor to improve the regional model for New Hampshire, through the State's Environmental Public Health Tracking Program, which is supported by the Centers for Disease Control (CDC). In New Hampshire, arsenic is more prevalent than in most other parts of New England and additional explanatory data currently exist that could be used to improve model predictions within New Hampshire. An improved ability to predict arsenic may have a significant positive effect on health outcomes by providing citizens, government agencies, and researchers with probability estimates and other information on this contaminant. The study objectives include assembling new arsenic data generated by the New Hampshire Environmental Health Tracking Program; development of an updated predictive model for arsenic in bedrock wells; and assessing the feasibility of applying this model to other contaminants as part of a proposed New Hampshire Atlas of drinking-water well contaminants. The other contaminants could include uranium, manganese, fluoride, lead, radon, nitrate, and VOCs, among others. More Information:
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Polar Organic Compounds in Surface Waters near Lead-Zinc Mining Operations in Missouri
Mining activities in many areas of the country are increasing due to the expanding market in Asia for the Nation's raw materials. One such area is the Old Lead Belt and its successor the New Lead Belt, in southeast Missouri. Both of these areas have a long history of lead-zinc mining, which released large quantities of solid wastes and toxic metals to the environment. Mining-related environmental studies have, therefore, focused on the characterizing the release of metals and other inorganic materials into the environment and the effects of these releases on air quality, water quality, and ecosystem health. Modern metal beneficiation processes, such as those employed in the mines and mills of the New Lead Belt in Missouri, have significantly improved and minimized the concentration of metals in the liquid wastes discharged from the beneficiation processes. However, these processes rely heavily on organic chemicals, such as xanthates, alcohols, and other reagents—compounds that are toxic to humans and wildlife. These compounds are called polar organic chemicals because they have a greater affinity for other organic matter than they do for water. USGS scientists have started a new study to investigate the occurrence of polar organic chemicals derived from metal beneficiation in streams draining active mine-mill complexes in the New Lead Belt area of southeast Missouri. The investigation will include onsite studies of streams, springs, and ground water; geologic mapping; research on the mobilization of trace elements during the mining of lead-zinc ore; the effect of tailing piles on stream water and sediment quality; surveys of stream biological quality and lead accumulation by aquatic biota; and research on the toxicity of lead and other heavy metals to aquatic biota. The study will determine if polar organic chemicals pose a health risk to downstream biota and drinking water sources. |
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Aquatic Life Exposed to Lead, Cadmium and Zinc in Missouri StreamsStreams draining a lead-mining district in southeast Missouri carry a burden of lead, cadmium and zinc, which can find their way into aquatic life. Elevated concentrations of lead, cadmium, and zinc were found in aquatic life that were above concentrations found in streams away from the mining areas according to a recent paper in Environmental Monitoring and Assessment by USGS scientists. These findings are significant because they demonstrate that heavy metals originating from long-term lead mining activity in southeast Missouri are available for bioaccumulation by stream life. The results of this study has led to further research on potential toxic effects of metals on aquatic life and bioaccumulation downstream of mining areas. |
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Citrus Pesticides in Ground Water and Lakes in Central Florida
The USGS is partnering with the Florida Department of Agriculture and Consumer Services Bureau of Pesticides and the Southwest Florida Water Management District to conduct an assessment of the susceptibility of ground water and lakes to pesticides and nutrients associated with citrus agriculture in central Florida. The sandy soils (Entisols) along the central Florida ridge systems are a mainstay of Florida's citrus agriculture. The Lake Wales Ridge, a representative area covered by one of the most extensive concentrations of citrus groves in the U.S., is vulnerable to leaching of chemicals such as pesticides and fertilizers. The ground-water system in the surficial (water table) aquifer, a source of rural water supply, is closely linked with the numerous lakes in the region and is hydraulically connected with the underlying Upper Floridan aquifer, the primary municipal water supply for the region. A network of wells has provided an "early warning" of pesticides leaching into ground-water resources. The detection of nitrate, pesticides, and pesticide degradates (chemicals formed by the degradation of pesticides) in ground water in this area confirm the vulnerability of the region. This will be the first survey of the occurrence of pesticides in the area's lakes. |
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Mussels are Disappearing in the U.S.
Freshwater mussels are rapidly declining in the United States, although not unique to North America, the decline in the United States is notable because mussels reach their greatest diversity here. USGS scientists and there partners have published a series of papers in Environmental Toxicology and Chemistry (see New Publications section), that discuss the development and applications of toxicity tests with early life stages of freshwater mussels. The new toxicity tests were use to assess the sensitivity of mussels to several contaminants, such as copper and ammonia. Their results indicate that national water-quality criteria for copper and ammonia may not be adequately protecting the mussel species they tested. |
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Endocrine Disruption Found in Fish Exposed to Municipal Wastewater
USGS scientists and their colleagues have found that exposure to the wastewater from a major metropolitan sewage treatment plant caused endocrine disruption in male fathead minnows. After exposure to the wastewater the male minnows started producing vitellogenin--a female egg-yoke protein. Treated wastewater discharge has been identified as a source of endocrine disrupting chemicals to the aquatic environment, and their study documents some of the potential effects, both positive and negative, in fish due to exposure to wastewater. More Information: |
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USGS Circular Wins Another AwardThe USGS publication Disease Emergence and Resurgence: The Wildlife-Human Connection (Circular 1285) by Milton Friend and others has recently been awarded The Best Book Award from The Wildlife Society. Works recognized by this award of excellence are scientific writing characterized by originality of research or thought and a high scholastic standard in the manner of presentation. In April, the National Association of Government Communicators awarded the book first place in the soft-cover book category. |
December 2006
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Breaking the Chain of Disease Transmission
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USGS Participates in Study of Leukemia ClusterBetween 1997 and 2001, 15 children were diagnosed with acute lymphocytic leukemia with one additional case of acute myelogenous leukemia in Churchill County, Nevada. This prompted an investigation by the Centers for Disease Control and Prevention and the eventual designation as a cancer cluster. A team of Nevada scientists from the University of Nevada, Reno and the U.S. Geological Survey will study whether compounds found in the drinking water of Churchill County residents potentially could have contributed to this cancer cluster. The investigators will collect and analyze both ground water and well water from around Churchill County for arsenic, tungsten and polonium-210, all potentially carcinogenic compounds. The sampling program will provide valuable information regarding the distribution of polonium-210 in Churchill County ground water. Water samples will also be used for animal-based toxicological testing by scientists at the University of Nevada, Reno. The results of this study, the second USGS water study in the Fallon area, are intended to inform resource managers and the public. |
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National Summary of the Quality of Domestic Well WaterData from over 18,000 wells were analyzed to develop the first national-scale retrospective of self-supplied drinking water sources. The study looked at a range of inorganic and organic compounds. Inorganic contaminants were detected in many well and concentrations exceeded USEPA drinking water standards more often than organic contaminants. The report was published in the journal Ground Water Monitoring & Remediation, volume 26, number 3. |
Volatile Organic Compounds in Our Ground Water
Pesticides in the Nation’s Streams and Ground Water
Most
newly emerging human diseases originate in animals and many disease agents can be transmitted between domestic
animals and wildlife. These disease agents have the potential to cause human illness or death, to impose heavy
economic costs on commercial agricultural, and threaten the sustainability of wildlife populations; and yet
little is known about the occurrence of these diseases in wildlife. USGS scientists at the
Beach Modeling Helps Swimmers Make Wise DecisionsJune 2006
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Human Exposure to Mercury in Ukraine
An integrated environmental/human health study is underway in Gorlovka, Ukraine, where elevated levels of mercury occur primarily due to past mercury mining and processing activities. Mine waste from mercury production, and current domestic and industrial use of coal from local sources, contribute to elevated levels of mercury in the environment. The study, Feasibility of Assessing Health Risks from Long-term Mercury Exposure in Gorlovka, Ukraine, funded by the U.S. Civilian Research and Development Foundation, has been incorporated into U.S. Geological Survey (USGS) project work on Health Effects of Energy Resources. The goals of the work in Gorlovka are to define levels of human exposure to mercury, assess possible health effects to exposed individuals, and determine the feasibility of larger scale epidemiologic studies.
The project involves U.S. participants from the USGS, the Armed Forces Institute of Pathology, and Sciences International, Inc., as well as Ukrainian scientists from the Academy of Medical Sciences of Ukraine Institute for Occupational Health, and Donetsk National Technical University. During a field visit to Gorlovka in August 2005, samples of hair, nails, blood, and urine were taken from a group of 30 workers at a mercury recycling facility on the site of the defunct Nikitovka mercury extraction plant. The scientists also collected environmental samples to assess mercury levels and potential exposure near the mercury mines and over a larger portion of Gorlovka. Further sampling will focus on Gorlovka residents lacking occupational mercury exposure, and residents of a nearby control municipality. This research has the potential to be an important human health case study of mercury exposure.
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Navajo Students Assist in Coal Combustion and Air Quality Study
USGS scientists are collaborating with the Navajo Nation Division of Health on respiratory health issues related to coal combustion products in ambient air and indoor air quality where coal is burned industrially and for home heating. USGS researchers will be assisted by Navajo students this summer (2006) to collect air samples. The samples will be analyzed and compared with samples collected this winter.
USGS Scientist Named Director of the International Medical Geology Association's North American Regional Division
The USGS's Joe Bunnell has accepted the nomination as Director of the newly established North American Regional Division
of the International Medical Geology Association (IMGA). The IMGA, formally
inaugurated in January 2006, now has established Regional Divisions throughout the world. The Association grew out of
interest in Medical Geology that continues to expand worldwide at an increasingly rapid rate. The IMGA should enable the
community to better respond to numerous opportunities, to rapidly pass information to those interested in Medical Geology
issues, and to make critical decisions that will benefit this emerging scientific discipline.
October-December 2004
Coccidioidomycosis: Mitigating the Risk
by Mark W. Bultman, Frederick S. Fisher, and Mark E. Gettings; Western Mineral Resources, Tuscan Arizona
Introduction
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In the upper 20 cm of some desert soils in the southwestern U.S., northern Mexico, and parts of Central and South America lives a dimorphic fungus that is the only eukaryote regulated under the U.S. Anti-terrorism and Effective Death Penalty Act. This fungus is Coccidioides and it is the etiological agent of coccidioidomycosis, also called valley fever. As it grows in the soil in its saprophytic phase, it is characterized by branching segmented hyphae that form a network of mycelium. As the fungus matures arthroconidia (spores), 2 to 5 microns in size, are formed as barrel shaped segments of the hypha (figure 1). The arthroconidia can be easily separated from the hypha by soil disturbance (natural or anthropogenic) and consequently dispersed by the wind. If an appropriate host inhales airborne arthroconidia, primary infection may occur and the parasitic phase of the Coccidioides lifecycle is initiated. Appropriate hosts include humans and other vertebrates. The life cycle of Coccidioides concludes with the death and subsequent decay of the infected host, returning the fungus to its saprophytic form in the soil.
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Character of coccidioidomycosis in humans
Coccidioidomycosis begins with the inhaled arthroconidia growing into spherules in the host’s lung tissue. The spherules mature, rupture, and release up to thousands of endospores. Each endospore can grow into a mature spherule and the infection propagates by this method. About 100,000 people are infected annually in the United States (Valley Fever Center for Excellence, 2002). Sixty to seventy percent of infected individuals will be asymptomatic and will develop long-lasting immunity. The remainder display symptoms that range from an influenza-like illness to over-whelming pneumonia starting 7-28 days after exposure. Most recover completely and develop long-lasting immunity. In a small number of cases (<1 percent), a progressive pneumonia can persist for months to years (Ampel, 2000). In about 0.5 percent of cases, the disease may disseminate into the skin, bones, soft tissue, or meninges (figure 2) and may require lifelong anti-fungal therapy. It can also disfigure, disable, or kill the infected individual.
The risk of developing active pulmonary coccidioidomycosis varies by age, gender, and, possibly, the level of exposure to the fungus. Figure 3 displays the incidence rate for coccidioidomycosis by age in Arizona from 1990 through 1995. Figure 3 clearly shows that elderly individuals are more susceptible to acquiring active coccidioidomycosis (CDC, 1996). Males tend to get coccidioidomycosis at a higher rate than females and diabetics tend to get a more serious form of pulmonary coccidioidomycosis than non-diabetics (Ampel, 2000). Also, in cases where there is a large exposure to inhaled arthroconidia, such as workers at an archeological dig, almost everyone exposed comes down with active pulmonary coccidioidomycosis (CDC, 2001). The risk of developing disseminated coccidioidomycosis varies by ethnicity and other factors. Blacks, Filipinos, Native Americans, males, and pregnant women in the second and third trimester are at an elevated risk for disseminated infection (Ampel, 2000). Those at the greatest risk from coccidioidomycosis (pulmonary and disseminated) are individuals with an underlying immunosuppressive condition (HIV/AIDS, lupus, organ transplants, chemotherapy, etc). In fact, disseminated coccidioidomycosis is commonly fatal in HIV patients. HIV infected patients with the non-meningitis form of disseminated coccidioidomycosis had a fatality rate of 68 percent and a median survival of 54 days (Aberg, 2003). Those with coccidioidal meningitis had a 33% fatality rate and a median survival of 6 months (Aberg, 2003).
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Coccidioidomycosis is a dangerous and expensive disease. Pappagianis (1980) estimated that the overall annual cost to the nation was one million person-days of labor. A review by the United States Centers for Disease Control and Prevention in Atlanta, Georgia (Goodman, ed., 1994) of the medical records in Kern County, California showed that coccidioidomycosis accounted for approximately $66 million in direct costs of hospitalization and outpatient care during the period 1991-1993.
Based on demographic trends in the United States an increasing number of previously un-exposed high-risk individuals (mostly elderly) are moving into endemic areas. In addition, recent changes in climate may favor infection. These factors have combined to create an increasing number of cases of coccidioidomycosis in the U.S. In 2001, the Arizona Department of Health Services reported an incidence of 43 cases per 100,000 population, a 186 percent increase in the incidence rate since 1998 (CDC, 2003).
Geology and ecology of Coccidioides sp.
The coccidioidomycosis endemic area is shown in figure 4. This area represents the geographical extent of environmental conditions favorable for Coccidioides to complete its life cycle in the soil. Coccidioidomycosis was entirely attributed to Coccidioides immitis until recently. Work by Fisher and others (2002) has provided evidence of two species of Coccidioides; Coccidioides immitis and Coccidioides posadasii. Coccidioides immitis is found in the central valley of California, southern California, and Mexico. Coccidioides posadasii is found in the parts of the endemic area outside the central valley of California (Fisher and others, 2002).
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Ongoing project work at the USGS Mineral Resource Program’s Southwest Field Office in Tucson, Arizona is aimed at 1) defining the geological/ecological habitat of Coccidioides sp.; 2) modeling that habitat with spatial and temporal models in order to map soils favorable for hosting Coccidioides sp. and delineating conditions where arthroconidia may be released into the atmosphere; and 3) with USGS Earth Surface Dynamics Program, to monitor and model dust emissions. The goal is to use this information to help mitigate coccidioidomycosis by predicting possible epidemics, sighting public facilities in areas where the fungus is not likely to be found, allowing biological and chemical control methods to be effectively utilized, and by allowing dust abatement methods to be used with greater effectiveness.
Laboratory and site-specific field studies have shown that many physical, chemical, climatic, and biological factors influence the growth of Coccidioides in the soil and the consequent development and deployment of arthroconidia.
With some exceptions endemic areas are generally arid to semiarid with low to moderate rainfall, mild winters, and long hot seasons. Mean annual soil temperatures range from 150°C to over 220°C. The presence of soils with textures that provide adequate pore space in the upper (20 cm) parts of the soil profile, for moisture, oxygen, and growing room is very important. Small amounts of clay foster water holding capacity, but large amounts of clay may be detrimental for Coccidioides growth. The presence of some organic material is needed for carbon and nitrogen but in most known occurrences it is generally sparse, less than 2%. Large amounts of organic compounds may be detrimental because they would foster the growth of bacteria and other fungal species that would compete with Coccidioides. Many Coccidioides growth sites have soils with elevated salinity, which may act an inhibitor of microbial competitors (Egeberg and others, 1964).
Detection of Coccidioides in the environment is difficult. Traditionally mice are inoculated with isolates from suspect soil. After a pre-determined time period the mice are sacrificed and their organs examined for evidence of infection as seen by the formation of the unique spherule form of Coccidioides. Recently, laboratories have turned to DNA analysis in an attempt to identify the cultured fungus. While there have been some successes using DNA, there is no standardized procedure and results so far are unreliable. Scientist collaborating with the USGS at the University of Arizona and the University of California Davis are working on the development and improvement of these new techniques. Presently, testing soil for the presence of Coccidioides is time consuming and difficult, thus there are few locations where it has been identified in the soil.
Coccidioides sp. habitat modeling
Habitat modeling of the saprophytic phase of Coccidioides is difficult, because of the limited number of places where it is known to exist in soil. This prevents the establishment of statistical relationships between growth sites and their physical, chemical, and biological habitat parameters. Therefore habitat modeling is accomplished using analysis of the physical properties of known Coccidioides sites within a spatial fuzzy system. A spatial fuzzy system is a system of spatial variables where some or all of the spatial variables are described with fuzzy sets. The fuzzy system is capable of translating structured knowledge into a flexible numerical framework and processing it with a series of if-then rules.
Fuzzy systems can describe non-linear numerical processes with linguistic common sense terms and can handle differing precision and accuracy in the data. They produce models that can be repeated and updated easily.
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A fuzzy system analysis was applied in Organ Pipe Cactus National Monument, Arizona. The resulting product is a map (Figure 5) depicting the favorableness of areas for hosting Coccidioides in soils based on a scale of 0 to 1, which we define as its fuzzy habitat suitability index. An important property of this kind of analysis is that “what if” scenarios can be used to predict changes in habitat with changing climate.
Complex systems modeling of the life cycle of Coccidioides
Like all environmental systems, the life cycle of Coccidioides is determined by a complex set of interactions between the organism and its surroundings. One concept that we are now testing is the possibility that saprophytic Coccidioides can reestablish itself in soil after arthroconidia have been blown to a new location by an extreme wind event. Fisher and others (2001) have shown that there is spatial genetic differentiation in Coccidiodes and geographically separate genetic clades are recognized in central California, southern California, Arizona, Mexico, Texas, and South America. This genetic differentiation argues against the ability of Coccidioides arthroconidia to reestablish themselves in soils, at least over long distances. But, spread of the fungus by wind may still be an important local process. In an attempt to model the spread and survival of the fungus Coccidioides in soil via wind-borne arthroconida transport, a complex systems model has been developed using public domain agent-based modeling software. The hypothetical model posits that for a successful new site to become established, four factors must be simultaneously satisfied. 1) There must be transport of arthroconidia from a source site to sites with favorable soil (physical, chemical, and biological properties). 2) There must be sufficient moisture for fungal growth. 3) Soil temperatures at the surface and at depth must be favorable for growth. Finally, 4) the temperature and moisture must remain in favorable ranges for a long enough time interval for the fungus to grow down to depths at which arthroconidia will survive subsequent heat, aridity, and ultraviolet radiation of the hot, dry season typical of the Southwest U.S. climate.
Numerous model runs have shown that the probability of new sites depends on the four factors in a Bayesian way. These results indicate that the complexity introduced in the model from site favorableness, temperature, moisture, and duration of favorable temperature and moisture conditions is adequate to explain distributions of real sites described in the literature and that wind transport at a local scale may be possible. We are now working on integrating more physical habitat factors as well as soil favorableness information into the complex systems model.
References
- Aberg, J.A., 2003, Coccidioidomycosis and HIV, HIV InSite Knowledge Base, University of California San Francisco, San Francisco, California.
- Ampel, N.M., 2000, Coccidioidomycosis, in Fungal Diseases of the Lung, Third edition, Sarosi, G.A. and Davies, S.F. editors, Lippincott Williams & Wilkins, Philadelphia.
- CDC, 2003, Increase in Coccidioidomycosis – Arizona, 1998-2001, in MMWR Series on public health and Aging, Morbidity and Mortality Weekly Report, Vol. 52, No. 6, Centers for Disease Control and Prevention, Atlanta, Georgia.
- CDC, 2001, Coccidioidomycosis in Workers at an Archeologic Site ---Dinosaur National Monument, Utah, June--July 2001, Morbidity and Mortality Weekly Report, Vol. 50, No. 45, Centers for Disease Control and Prevention, Atlanta, Georgia.
- CDC, 1996, Coccidioidomycosis -- Arizona, 1990-1995, Morbidity and Mortality Weekly Report, Vol. 45, No. 49, Centers for Disease Control and Prevention, Atlanta, Georgia.
- Egeberg, R. O., Elconin, A. E., and Egeberg, M. C., 1964, Effect of salinity and temperature on Coccidioides immitis and three antagonistic soil saprophytes: Journal of Bacteriology, v. 88, n. 2, p. 473 - 476.
- Fisher, M.C., Koenig, G.L., White, T.J., Taylor, J.W., 2002, Molecular and phenotypic description of Coccidioides posadasii sp. nov., previously recognized as the non-California population of Coccidioides immitis, in Mycologia, 94(1), pp. 73–84, The Mycological Society of America, Lawrence, Kansas.
- Fisher, M.C., Koenig, G.L., White, T.J., San-Blas, G., Negroni, R., Gutierez Alvarez, I., Wanke, B., and Taylor, J.W., Biogeographic range expansion into South America by Coccidioides immitis mirrors New World patterns of human migration, proceedings of the National Academy of Sciences of the United States of America, Vol. 98, No. 8, National Academy of Sciences, Washington, D.C.
- Goodman, R.A., editor, 1994. Emerging Infectious Diseases, Update: Coccidioidomycosis - California, 1991-1993: Centers for Disease Control and Prevention, Morbidity and Mortality Weekly Report, v. 43, n. 23, p. 421-423.
- Pappagianis, Demosthenes, 1980, Epidemiology of coccidioidomycosis: in Stevens, D. A., editor, Coccidioidomycosis, Plenum Medical Book Company, New York, p. 63 - 85.
- Valley Fever Center for Excellence, accessed October 2003, http://vfce.arl.arizona.edu, Southern Arizona VA Health Care System, Tucson, Arizona.
Formation of new USGS Human Health Coordination Committee
Charles G. Groat (signed) Chip Groat Director, USGS
I am pleased to announce that Herb Buxton has agreed to chair a USGS Human Health Coordination Committee. This committee, comprising program coordinators who currently support Human Health research, will work to increase coordination with human health agencies and coordination among USGS human health related activities. Some of the committee’s first tasks will be to develop long-term strategies to identify focused research areas for the USGS, to strengthen our partnerships with human health agencies, and to identify opportunities for additional funding and growth. As chair of the Human Health Coordination Committee, Herb’s first task will be to work with the Associate Directors to assemble the group. He will also serve as the USGS point of contact for health agencies and facilitate interdisciplinary response to their needs. Currently, Herb manages the Toxic Substances Hydrology Program and he will continue in that role concurrently.
Human health issues are a high priority for the American people, and, as a Federal agency, the USGS can provide critical science information in this area. However, many of our capabilities are underutilized, particularly in the areas of wildlife health-human health interactions and the use of our environmental databases (water quality, rock and soil geochemistry, land cover, etc). To maximize our impact, we must partner with the health sciences and medical fields to understand their information needs and to educate them about the value USGS can add.
As the Toxics Program Coordinator, Herb has worked closely with environmental and human health agencies on topics such as mercury cycling in aquatic ecosystems, contamination from hardrock mining, MTBE, pesticides and their degradation products, and pharmaceutically and hormonally active contaminants. He received his B.S. in Geology from Rensselaer Polytechnic Institute, and his M.S. in Geology from the State University of New York. After working as a research associate at the University of South Carolina’s Hydrogeology Program, he has had a 25-year career with the USGS as a scientist and manager.
Please join me in welcoming Herb to this new leadership role.
July-September 2003
Pharmaceuticals, Hormones, Personal-Care Products, and other Organic Wastewater Contaminents in Water Resources: Recent Research Activities of the U.S. Geological Survey's Toxic Substances Hydrology Program
By Michael J. Focazio, Dana W. Kolpin, and Herb Buxton
Recent decades have brought increasing concerns for potential contamination of water resources that could inadvertently result during production, use, and disposal of the numerous chemicals offering improvements in industry, agriculture, medical treatment, and even common household products. Increasing knowledge of the environmental occurrence or toxicological behavior of these contaminants from various studies in Europe, United States, and elsewhere has resulted in increased concern for potential adverse environmental and human health effects (Daughton and Ternes, 1999). Ecologists and public health experts often have incomplete understandings of the toxicological significance of many of these contaminants, particularly long-term, low-level exposure and when they occur in mixtures with other contaminants (Daughton and Ternes, 1999; Kümmerer, 2001). In addition, these ‘emerging contaminants’ are not typically monitored or assessed in ambient water resources. The need to understand the processes controlling the transport and fate of these contaminants in the environment, and the lack of knowledge of the significance of long-term exposures have increased the need to study environmental occurrence down to trace (nanogram per liter) levels. Furthermore, the possibility that mixtures of environmental contaminants may interact synergistically or antagonistically has increased the need to characterize the types of mixtures that are found in our waters. The U.S. Geological Survey’s Toxic Substances Hydrology Program (Toxics Program) is developing information and tools on emerging water-quality issues that will be used to design and improve water-quality monitoring and assessment programs of the USGS and others, and for proactive decision-making by industry, regulators, the research community, and the public (http://toxics.usgs.gov/regional/emc/). This research on emerging water-quality issues includes a combination of laboratory work to develop new analytical capabilities as well as field work on the occurrence, fate, and effects of these contaminants.
LABORATORY WORK
Analytical Method Research and Development
Since 1998, the Toxics Program has been developing analytical capabilities to measure pharmaceuticals, personal care products, hormones, and other naturally occurring and synthetic organic wastewater compounds (collectively referred to as OWCs) in a variety of environmental matrices (water, sediment, tissue). Without reliable and accurate analytical methods the corresponding field research would be impossible. Currently, more than 140 OWCs can be measured by the U.S. Geological Survey using a variety of liquid and gas chromatographic techniques (e.g. Brown et al., 1999; Barber, et al., 2000; Meyer et al., 2000, Lindsey et al., 2001, Zaugg et al., 2002). Analytical methods are being developed and improved for whole water, filtered water, and bed sediment samples. These methods are capable of detecting OWCs at sub part-perbillion levels in a wide range of natural and anthropogenically impacted waters of variable chemistry and quality. To date, these analytical methods have provided the necessary tools to support field investigations on the occurrence of OWCs in the environment and have begun to support new research projects focused on fate, transport, and effects.
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FIELD WORK
National Reconnaissance Surveys
To date, over 500 environmental samples have been collected for the Toxics Program and analyzed for OWCs, representing a broad range of climatic and hydrogeologic conditions. Initial and continuing research has focused on broad reconnaissance surveys of streams, aquifers, and sources of drinking water to determine if these emerging contaminants are entering the Nation’s water resources and if so, at what concentrations and combinations. The surveys are not representative of all water resources in the United States, but do provide the first information on the occurrence of a large range of OWCs in the Nation’s water resources. This work helps researchers develop hypotheses on the sources, fate and transport of OWCs in the environment.
The first reconnaissance survey completed consisted of a network of 139 streams across 30 states sampled during 1999 and 2000 (Barnes et al., 2002; Buxton and Kolpin, 2002; Kolpin et al., 2002a; Kolpin et al., 2002b). By design, most streams sampled were known or suspected to be susceptible to sources of human, animal or industrial wastewater (Fig. 1). Results showed that a broad range of chemicals found commonly occurs in mixtures at low concentrations downstream from areas of intense urbanization and animal production. One or more of the 95 chemicals analyzed were found in generally low concentrations in 80 percent of the streams sampled. Half of the streams contained 7 or more of these chemicals, and about one-third of the streams contained 10 or more of these chemicals. Some of the most frequently detected compounds (Fig. 2) included cholesterol (naturally occurring plant and animal steroid), DEET (an insect repellent), caffeine (nonprescription drug), triclosan (antimicrobial disinfectant), and tri (2-chloroethyl) phosphate (fire retardant). Two additional reconnaissance surveys have also been conducted. In 2000, a network of 47 ground-water sites downgradient from, or near, landfills, unsewered suspected to be susceptible to contamination (e.g. residential developments, animal feedlots, etc.) across 18 states was sampled and measured for OWCs (Barnes et al., 2003). In 2001, a network of 76 drinking-water sources (51 surface-water sources and 25 ground-water sources) across 25 states and Puerto Rico was sampled and measured for OWCs (Focazio et al., 2003). All samples for this survey were collected prior to any water treatment practices (e.g. river intakes and raw-water sampling ports). This survey of drinking-water sources was conducted in collaboration with the U.S. Environmental Protection Agency and with assistance from the American Water Resources Association. The results of these two additional reconnaissance surveys are currently being examined and interpreted.
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Sources, Fate, and Transport
Subsequent and planned research is focused on potential sources of OWCs (e.g. animal feeding operations, fish hatcheries, wastewater treatment plants, etc.) and their fate and transport through the hydrologic system (Campagnolo et al., 2002; Cordy et al., 2002; Patterson et al., 2001; Thurman et al., 2002). Current research includes the collection of both stream water and bed sediment samples to provide a more complete understanding of the occurrence of OWCs and their partitioning in the environment.
CONCLUSION
Research conducted by the USGS’ Toxic Substances Hydrology Program addresses emerging water-quality issues associated with environmental occurrence of pharmaceuticals, hormones, personal care products, and other naturally occurring and synthetic organic wastewater compounds. This research provides new insights on the extent to which chemicals used every day in households, industry, and agriculture are entering and being transported in our water resources. These studies are among the first to address these issues and therefore provide unique data and information for other scientists as well as decision makers in the public and environmental health communities. For more information go to http://toxics.usgs.gov.
REFERENCES
- Barber, L.B., Brown, G.K., and Zaugg, S.D., 2000, Potential endocrine disrupting organic chemicals in treated municipal wastewater and river water: Chapter 7, in Keith, L.H., Jones-Lepp, T.L., and Needham, L.L. eds., Analysis of Environmental Endocrine Disruptors, American Chemical Society Symposium Series 747, American Chemical Society, Washington, DC, p. 97-123.
- Barnes, K.K., Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., and Zaugg, S.D., 2003, A national reconnaissance for pharmaceuticals and other organic wastewater compounds in ground water, in Third International Conference on Pharmaceuticals and Endocrine Disrupting Chemicals in Water, National Ground Water Association, March 19-21, 2003, Minneapolis, Minnesota.
- Barnes, K.K., Kolpin, D.W., Meyer, M.T., Thurman, E.M., Furlong, E.T., Zaugg, S.D., and Barber, L.B., 2002, Water quality data for pharmaceuticals, homones, and other organic wastewater contaminants in U.S. streams, 1999- 2000: U.S. Geological Survey Open-File Report 02-94.
- Brown, G. K., Zaugg, S. D., Barber, L. B., 1999, Wastewater analysis by gas chromatography/mass spectrometry, U.S. Geological Survey Toxic Substances Hydrology Program Proceedings of the Technical Meeting, Charleston, South Carolina, March 8-12, p. 431-435.
- Buxton, H.T. and Kolpin, D.W., 2002, Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams: USGS Fact Sheet FS-027-02.
- Campagnolo, E.R., Johnson, K.R., Karpati, A., Rubin, C.S., Kolpin, D.W., Meyer, M.T., Esteban, J.E., Carter, R.W., Smith, K., Thu, K.M, and McGeehin, M., Antimicrobial residues in animal waste and water resources proximal to large-scale swine and poultry feeding operations, 2002, The Science of the Total Environment, Vol. 299, p. 89-95.
- Cordy, G., Duran, N., Bouwer, H., Rice, R., Adamsen, F., Askins, J., Kolpin, D.W., Furlong, E.T., Zaugg, S.D., Meyer, M.T., Barber, L.B, 2002, Do pharmaceuticals, pathogens, and other organicwastewater contaminants persist when wastewater is used for recharge? in Tembly, Jeff, compiler, Symposium 2002--Water Transfers: Past, Present, and Future: Proceedings of the fifteenth annual symposium of the Arizona Hydrological Society, Flagstaff, AZ, Sept. 18-21, 2002, p. 105-109.
- Daughton, C.G., and Ternes, T.A., 1999. Pharmaceuticals and personal care Products in the environment: Agents for subtle change?: Environ. Health Persp. Vol. 107.
- Focazio, M.J., Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., and Zaugg, S.D., 2003, A national reconnaissance for pharmaceuticals and other organic wastewater compounds in untreated drinking water sources, in Third International Conference on Pharmaceuticals and Endocrine Disrupting Chemicals in Water, National Ground Water Association, March 19-21, 2003, Minneapolis, Minnesota.
- Kolpin, D.W., Furlong, E.T, Meyer, M.T., Thurman, E.M., Zaugg, S.D., Barber, L.B., and Buxton, H.T., 2002a. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. Streams, 1999-2000: A national reconnaissance. Environ. Sci. Technol. Vol. 36, p. 1202-1211.
- Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., Zaugg, S.D., Barber, L.B., and Buxton, H.T., 2002b, Response to comment on "Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance": Environ. Sci. Technol., v. 36, n. 18, p. 4007-4008. Kümmerer, K. (Ed.) Pharmaceuticals in the Environment: Sources, Fate, Effects and Risks, 2001. Springer-Verlag, 2001
- Lindsey, M.E.; Meyer, M.; Thurman, E.M. 2001, Analysis of trace levels of sulfanamide and tetracycline antimicrobials in groundwater and surface water using solid-phase extraction and liquid chromatography/mass spectrometry. Anal. Chem., 73, 4640-4646.
- Meyer, M.T.; Bumgarner, J.E.; Varns, J.L.; Daughtridge, J.V.; Thurman, E.M.; and Hostetler, K.A. 2000, Use of radioimmunoassay as a screen for antibiotics in confined animal feeding operations and confirmation by liquid chromatography / mass spectrometry. Sci. Total Environ., 248, 181-187.
- Patterson, G., Kolpin, D.W., Kalkhoff, S.J., Lee, K., Schnoebelen, D., Barnes, K.K., and Coupe, R., 2001, It's not just how high; it's how clean: Sampling the spring 2001 flood in the Upper Mississippi River Basin: EPA Watershed Events, EPA 840-B01-001, Summer 2001, 3-4.
- Thurman, E.M., J.E. Dietze, and E.A. Scribner, 2002, Occurrence of antibiortics in water from fish hatcheries, U.S. Geological Survey, Fact Sheet 120-02, 4 p.
- Zaugg, S.D., Smith, S.G., Schroeder, M.P., Barber, L.P., and Burkhardt, M.R., 2002, Methods of analysis of the U.S. Geological Survey National Water Quality Laboratory—Determination of Wastewater Compounds by Polystyrene-Divinylbenzene Solid-Phase Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry, 2002, U.S. Geological Survey Water-Resources Investigations Report 01-4186, 37 p.
Mendenhall Postdoc Program Supports GeoHealth Science
By Christina Kellogg
Since its inception in 2001, the Mendenhall postdoctoral program has been an avenue for bringing young scientists with new talents and skills into the Geologic Discipline of the USGS. Named in honor of Walter Mendenhall, the fifth Director of the USGS, this program is now moving into its fourth year.
Three of the first year Mendenhall Fellows, Thomas L. Ziegler (Denver), Christina A. Kellogg (St. Petersburg) and Joseph E. Bunnell (Reston), gave talks during the recent USGS Conference ‘Natural Science and Public Health—Prescription for a Better Environment.’ The meeting, which focused on the intersection of environmental research and human health, an important venue to highlight the significance of their research.
While all three work in the Geologic Discipline, not one is a geologist! Thomas is a toxicologist by training, Chris is a molecular microbiologist, and Joe is a public health biologist. They all play a significant role in linking geoscience with other disciplines.
Joe presented his research first, titled ‘Environmental Predictors for Tick-borne Disease Risk in the Middle Atlantic Region, USA.’ Lyme disease, the most common vector-borne disease in the U.S., and ehrlichiosis, an emerging deadly disease, are both bacterial infections that are spread by ticks. In an effort to better quantify the risk factors associated with certain areas, a spatial statistical model incorporating factors such as elevation, soil type and features (texture, waterincluded holding capacity), land cover, and proximity to forests or water bodies, was used to predict areas most supportive to tick populations. The predictions from this model can help target more effective intervention actions and hopefully reduce the number of cases of tick-borne disease.
Chris discussed the long-distance transport of microbes in dust from the Sahara/Sahel region ofAfrican in her presentation titled “Out of Africa: Characterization of Microbial Communities Associated with Desert Dust and Their Implications for Human and Ecosystem Health.’ Each year, millions of tons of desert soil dust blow off the west African coast and ride the trade winds across the Atlantic Ocean, routinely impacting the Caribbean and southeastern United States. This dust has been shown to carry living microorganisms, including a wide variety of bacteria and fungi, some of which are capable of causing disease in plants, animals, and humans with weakened immune systems. It is important to characterize and quantify these airborne microbes to assess what effects they may have on downwind ecosystems.
Asbestos is a general term for a group of fibrous silicate minerals used in many construction materials due to their fire-resistant nature. Asbestos can be divided into two mineral groups, serpentine and amphibole, based on the crystalline structure. Serpentines have a sheet or layered structure, while amphiboles have a chain-like structure. In spite of its many applications, usage has declined due to links between asbestos and diseases including lung cancer. In his talk titled, “Mineralogical, Geochemical, and Toxicological Variations of Asbestos Toxicological Standards and Amphibole Samples from Libby, MT,” Thomas described how asbestos standards are not as uniform as one would expect. In fact, the chemical analyses of a series of asbestos standards (amosites, anthophyllites, chrysotiles, crocidolites and tremolites) indicated that elemental content varied within standards of the same mineral. Furthermore, each asbestos mineral, even those labeled as the same mineral, has its own profile of accessory minerals which may play a role in the wide range of toxicity seen in the cell line toxicity data presented and possibly explain some of the conflicting reports for asbestos toxicity found in the literature. In addition, toxicity data was presented for the Libby, MT amphibole that was revealed to be significantly more toxic than the asbestos standards in comparison.
In addition to the 20 minute talks given during the conference, both of the ‘out-of-towners’ gave hour-long lectures about their Mendenhall research in the USGS Visitors Center; Thomas spoke the Monday before the conference, and Chris followed on the Friday after. For more information on the Mendenhall program, including profiles of the Fellows and their research projects, please visit the web site: http://geology.usgs.gov/postdoc/ or contact Rama Kotra (rkotra@usgs.gov).
November 1, 2002
Weathered Lignite Deposits and Balkan Endemic Nephropathy
by Gerald L. Feder
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Balkan endemic nephropathy (BEN) is a fatal kidney disease that is known to occur only in geographically discrete areas of the Balkan Peninsula in Eastern Europe. The disease was first described in 1956, but may have existed for many centuries. The disease seems to occur only in rural villages located on alluvial valleys of tributaries of the lower Danube River (Figure 1). Although the disease is apparently geographically restricted to a relatively small area, BEN is a significant public health problem. At least 25,000 people are believed to be suffering from BEN, and over 100,000 people may be at risk. Researchers have been trying to determine the cause(s) of BEN for almost half a century, but there is still no consensus among the scientific community as to its etiology. Some local villagers feel that mysterious cosmic powers are responsible, and wear protective amulets or pendants and perform ritual prayers to ward off the disease. Western medicine generally opines that certain environmental exposures, genetic predisposition, and/or an infectious agent is the more likely cause.
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A common geologic feature of endemic villages is the proximity to distinctive low rank Pliocene lignite deposits and lignitic shales that were deposited about 5.3 to about 1.6 million years ago. Researchers at USGS hypothesize that weathering of the lignites and associated shales yield toxic soluble organic compounds, and that these toxins are transported by the local ground water flow system to the shallow water wells used by the villagers. Figure 2 shows an alluvial valley typifying the geologic and hydrologic setting of endemic home sites.
Laboratory analysis at USGS of water samples from endemic and nonendemic villages indicate the presence of potentially carcinogenic and nephrotoxic organic compounds (Figure 3). These include napthylamines, aniline, aminophenols, alkyl phenols, biphenyls, and heterocyclic (N-, O-, and S containing) compounds in much higher concentrations in the endemic villages than nearby non-endemic villages.
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The disease has several features that characterize it as a distinct clinical entity. Unlike the case with many other kidney disorders, BEN patients do not, as a rule, have high blood pressure. And a significant number of BEN patients also have an otherwise unusual type of upper urinary tract cancer. Only stable, rural populations of people seem to get BEN. The stability implies a long “incubation period” for the disease, consistent with ingesting low levels of toxic compounds from rural water wells over decades. There are no known cases of BEN among people living in cities and drinking water from a municipal supply. Making the diagnosis of BEN is made challenging by the lack of any specific sign, or marker of the disease. Only when the particular constellation of symptoms and the patient’s history are in keeping with BEN is the diagnosis made. Thus there could be many more people suffering from BEN than is currently recognized. Autopsies are not routinely performed in this region, and only a post-mortem examination can confirm BEN as the cause of death. The kidneys are shrunken to about 30% their normal size. BEN patients in some areas now undergo new sophisticated ultrasound procedures to help confirm the presence of shrunken kidneys, and the proper diagnosis of BEN.
The clinical and pathological characterization of the disease has been followed by a sustained search for its causative factors, involving international teams and multidisciplinary approaches. At present, fatalities from BEN still occur in the same regions, and the etiology of the disease is still not known. The main fruits of BEN research, up to the present, have come mostly from excluding some fruitless hypotheses, and to redirect future investigations and hypotheses. A currently accepted concept is that BEN is an environmentally induced disease, and some of the most consistently incriminated agents are toxic organic compounds present in the drinking water from shallow wells in the endemic areas. Researchers at USGS hypothesize that these compounds may be leached by groundwater flowing through the nearby low rank Pliocene coal (lignite) deposits, and transported into shallow household wells dug into the alluvium. Until the past decade, most people in the endemic villages used water from these shallow hand dug household wells, for drinking and other purposes. Over the past decade an increasing number of endemic villages are getting public surface water supplies, piped in to household faucets from regional surface water reservoirs. These reservoirs are quite distant from the endemic villages, and are filled by surface water runoff that is independent of the ground water system supplying the wells in the endemic villages. Moreover, the treatment process for this water renders formerly toxic compounds harmless. It will be very useful to study the people in these villages to see if the people raised from childhood using piped-in water no longer develop BEN.
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One of the characteristics of BEN is that people generally don't develop the disease unless they have lived in an endemic village for the first 15-20 years of their life. They then generally won't develop the disease until they are about 40 to 50 years old. Once they develop the disease, it is fatal, unless they go on dialysis, or get a kidney transplant. Due to the high cost of kidney transplants, and the low economic status of most villagers in the endemic areas, most patients must spend the rest of their lives on dialysis. Many BEN cases are reported where a person moves out of an endemic village at about 20 years of age, and they are later diagnosed with the disease when they are about 40 or 50 years old. Though the correlation between endemic villages and the proximity to Pliocene lignite deposits seems to be established, many researchers believe BEN may be a multicausal disease. For example, genetic factors may predispose a person to develop BEN if they are exposed to certain toxic organic compounds early in their lives, or even prenatally. Similarly, it is possible that childhood exposure to fungal toxins known to damage the kidneys or infection with bacteria that attack the kidneys sets one up for developing BEN. Subsequent long term exposure to low levels of toxic organic lignite-derived compounds may then seal the person’s fate, leaving unharmed someone with no such history.
While BEN is not known to occur in the United States, it is curious that this country’s lignite deposits occur in states with the highest rates of cancers of the renal pelvis (RPC). Louisiana has the sixth highest Renal Pelvic Cancer (RPC) mortality rate in the United States. Other states with major lignite deposits are Wyoming and the Dakotas; Wyoming ranks first in the USA for RPC, and North and South Dakota rank third and fourth, respectively. All of these states have large rural populations that obtain drinking water from wells. A team of scientists from USGS, the Louisiana Geological Survey, the Centers for Disease Control and Prevention, and the Louisiana State University Medical School have begun investigations designed to see if a BEN-like syndrome exists in this country. It will also be instructive to look closely at countries with large lignite deposits like Greece and Turkey. However, health data from these nations are sometimes unreliable, and are often difficult to obtain.
While a clear understanding of the cause(s) of BEN remains elusive, there is good reason to be hopeful that we will soon identify the risk factors, and enable preventative measures that will protect large numbers of people from this illness. This issue represents an example of how geoscience experts and the public health and biomedical community need to communicate, cooperate, and collaborate to untangle the intricacies of complex disease etiologies having an environmental component. That is to say, for all of the misery it brings, BEN does seem to be a valuable mechanism for Epidemioecologists to demonstrate their worth.
Jerry Feder, one of the world's foremost BEN investigators and has retired from the USGS, but may still be contacted at glfeder@tu.infi.net or gl9202@aol.com. A fact sheet summarizing BEN may be found at http://pubs.usgs.gov/fs/fs004-01.
August 1, 2002
The Movement of Soil and Sediment in Earth’s Atmosphere: Microbiology and Ecosystem Health
D.W. Griffin, C.A. Kellogg, V.H. Garrison, C. Holmes, and E.A. Shinn
A rain of dirt
While soils and sediments in Earth’s atmosphere originate from arid regions around the globe, the majority of ‘dust’ originates from two locations, the Sahara and Sahel regions of Africa and the deserts of Asia. Dust storms originating in the arid regions of North Africa occur year round and account for approximately 75% of all soils and sediments lifted into our atmosphere. In the months from June through October dust originating from Africa routinely impacts the Caribbean, Central and North America. In the remaining months the African dust storms typically impact South America, Europe and the Middle East. Dust storms originating in the Asian deserts usually occur from February through April of each year. While the Asian deserts are smaller than the Sahara and the dust season is only three months long, they are a significant source of airborne soils and sediments.
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The current estimate on the quantity of soil moving some distance in Earth’s atmosphere each year is approximately 2 billion metric tons and some feel that this may be a significant underestimate (Figure 1. A dust cloud the size of Spain rolling off the Western coast of the Sahara Desert). If you converted that 2 billion ton estimate into Volkswagen Beetles (based on weight), that would be enough Beetles to create a 119 meter tower over the entire 176 km2 surface area of Washington, D.C. From a microbiology perspective there is an additional piece of trivia - the 2 billion ton estimate converts to 2 quadrillion grams. At a conservative estimate of 10,000 bacteria per gram, that’s enough bacteria, if placed end to end, to form a microbial bridge between Earth and Jupiter. Additionally, such dust also transports fungal and viral microbial pathogens. With respect to human and ecosystem health, one has to ask what percentage of the associated microbial population is pathogenic and how many of these disease-causing microbes are capable of surviving long range airborne transport? What risks do these and other potential hazards such as herbicides, pesticides and radioisotopes that have also been identified in dust clouds pose to impacted populations of humans and ecosystems? These are questions with global implications, questions that are being addressed by a surprisingly small number of researchers.
The Good
The movement of soils and exposed sediments in atmospheres is a natural planetary process; Martian dust devils as imaged by NASA’s interstellar exploration efforts are a prime example. Analysis by researchers on ice cores taken in the Arctic and Antarctic have demonstrated periods of both heavy and light global dust transport as Earth has evolved to our current point in time. Terrestrial and aquatic plant life have evolved to take advantage of the nutrient-rich particles (iron, phosphate and organic detritus) in clouds of dust that fall out of the atmosphere. Research has shown that plant life in the upper canopy of the South American rain forest derive their nutrients from African dust. Rain forests located on the Northern Hawaiian Island chain are believed to obtain a significant fraction of their nutrient budget from Asian desert dust. Researchers are currently investigating the influence of nutrient-laden dust on growth of phototrophic microorganisms in oligotrophic regions of our oceans. The deposition of clay-laden African dust on Caribbean Islands through time enabled ‘Pre-Columbian’ Indians to produce pottery from an otherwise clay-limited soil. Clearly the global movement of dust has benefited both ecosystems and humanity.
The Bad and the Ugly
One of the first links to be made between long range transport of desert dust and ecosystem health was the isolation and identification of a terrestrial fungus (Aspergillus sydowii) as the causative agent of the Caribbean-wide seafan disease agent from atmospheric samples collected in the United States Virgin Islands. There is a replete history of research that has implicated long-range dispersion fungal pathogens of plants and crops over vast expanses of terrestrial and marine environments. In the 1970’s sugarcane rust caused by Puccinia melanocephala was surmised to have spread from Africa to the Caribbean and then to North America via airborne transport. Similarly, the coffee rust agent Hemileia vastatrix was suspected of being delivered from Africa to the Caribbean via the atmosphere. Outbreaks of foot-and-mouth disease have been reported in Korea following large dust events originating in China’s deserts. Research on the source of the pseudorabies virus (cause of Aujeszky’s disease in pigs) after outbreaks occurred in Denmark in December of 1988 concluded that the infections were probably due to atmospheric transport of the viral pathogen from Germany. Recent research conducted at the University of South Florida’s Department of Marine Sciences has implicated African dust deposition and outbreaks of harmful algal blooms (red tide) along Florida’s coastline.
The National Institute of Allergy and Infectious Diseases identifies airborne dust as the primary source of allergic stress worldwide. Areas such as the Aral Sea (The Aral Sea, along with other inland bodies of water such as Lake Chad in Africa and Lake Owens in California, are significant sources of dust due to the fine nature of exposed sediments produced by drought and/or source water diversion, i.e. falling water tables) and the Caribbean, where desert dust activity is common, have some of the highest recorded incidence rates of human asthma on the planet. Barbados experienced a 17-fold increase in the incidence rate of asthma from 1973 to 1996. This observed increase in incidence coincided with the increased dust flux from the Sahara and Sahel to the Caribbean. A number of diseases such as ‘Al Eskan Disease’ a.k.a. ‘Desert Storm Pneumonitis,’ and ‘Desert Lung Syndrome’ have been attributed to exposure to atmospherically suspended desert dusts. Exposure to airborne dust containing bacterial endotoxin and mycotoxins produced by fungi is known to cause disease and death. Large outbreaks of meningococcal meningitis (caused by the bacterium Neisseria meningitidis) resulting in both illnesses and death are routinely reported in West African countries following dust events. In the Americas, small outbreaks of coccidioidomycosis (caused by the fungal pathogen Coccidioides immitis) following dust events are common. Widespread use of pesticides and herbicides in farming and the subsequent airborne transport of toxin-laden soils pose a risk to human health. People living in the vicinity of the Aral Sea have suffered from illnesses due to the organosphosphate pesticide phosalone exposure. Analysis of human breast milk collected from women in southern Kazakhstan found levels of beta-hexachlorocyclohexane (an organochlorine pesticide residue) that were some of the highest concentrations published in scientific literature. Additional research in the region found high concentrations of this pesticide residue and dichloro-diphenyltrichloroethane (DDT) compounds in children’s blood. The Arctic is impacted by pesticide and herbicide-laden clouds of desert dust originating from both Asia and Africa where they are used to maximize crop yield and, ironically, to counter other threats to public health. Pesticides in Arctic animals and Inuit Indian breast milk have been documented. A recent concern in long range dust movement and those populations persistently exposed to these dust particulates is recent evidence that isotopes such as beryllium-7 may accumulate on dust particles as they move through the atmosphere. While the potential risk to human populations is not presently clear, this emerging issue in global dust movement is a research area of much concern.
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Atmospheric Soils and Sediments and the USGS
Our research group at the USGS, Center for Coastal and Regional Marine Studies has documented increases in the numbers of airborne microorganisms in the US Virgin Islands, when the region is being impacted by African dust. The US Virgin Island data has shown that during dust events the number of organisms that can be cultured or observed using nucleic acid stains typically ranges from 2 to 10 times what is seen during normal/clear conditions (similar wind velocity and directions as seen during a dust event). Due to collaborative efforts, we are also currently conducting research in Mali, Africa and on the Mediterranean coastline of Turkey. These projects have been undertaken in order to understand the significance of what we are observing in the Caribbean versus dust cloud point of origin (Mali) and regions being impacted that are in closer proximity to the source (Turkey). We are also collaborating with NASA and the US Air Force to address the presence of microorganisms moving in Earth’s atmosphere at high altitudes. Data obtained from Mali samples (Figure 2) indicates that approximately 90% of the organisms that start the airborne trip in Africa die before they reach our Caribbean sample site. While this may seem significant one should keep in mind that a single gram of soil contains on average of approximately a million bacteria cells and with a die off rate of 90%, that still leaves 100,000 viable bacteria -- and that’s just in a single gram! Of those US Virgin Island isolates we have identified using DNA sequencing of the ribosomal gene, ~20% are species known to cause disease in a broad range of plant life and ~10% are known opportunistic human pathogens. New efforts undertaken this summer include DNA fingerprinting of the entire microbial community captured in our air samples (in order to identify uncultivable populations) and analysis of the previously observed viral community which are known to be present in our samples (microscopy and molecular techniques to define the virus community). Samples for use in screening dust events for pesticides and herbicides are currently being collected in the US Virgin Islands and radioisotope work on dust samples has shown extremely high levels of beryllium-7 and lead-210.
This is but a short synopsis of where what our research has shown us and where it is leading us. Our focus is currently human and ecosystem health (particularly coral reef health) as it relates to the long-range transport of African dust. Future efforts should expand into the Asian dust arena and collaborative efforts with USGS scientists currently involved in understanding dust issues in the American Midwest. For more specific information on our research data and the world of dust and health please see the following articles or website.
More Information
- Griffin, D.W., C.A. Kellogg, V.H. Garrison and E.A. Shinn. 2002. The Global Transport of Dust: An atmospheric river of dust, microorganisms and toxic chemicals crosses oceans. American Scientist. 90(3):228-235
- Griffin, D.W., V.H. Garrison, J.R. Herman and E.A. Shinn. 2001. African Desert Dust in the Caribbean Atmosphere: Microbiology and Public Health. Aerobiologia. 17(3):203-213
- Griffin, D.W., C.A. Kellogg, and E.A. Shinn. 2001. Dust in the Wind: Long Range Transport of Dust in the Atmosphere and its Implications for Global Public and Ecosystem Health. Global Change and Human Health. 2(1):20-33
- Shinn, E. A., G.W. Smith, J.M. Prospero, P. Betzer, M.L. Hayes, V. Garrison, and R.T. Barber. 2000. African Dust and the Demise of Caribbean Coral Reefs. Geological Research Letters 27: 3029-3032.
- Coral Mortality and African Dust -- http://coastal.er.usgs.gov/african_dust/
Acknowledgements
Our research has been supported by funding from NASA’s Earth Science and Public Health Program (grant # 7242-60050).
Hormone Disruption Research Act of 2002
HR 4709 was introduced in the House on May 9,2002, to amend the Public Health Services Act to authorize the Director of the National Institute of Environmental Health Sciences (NIEHS) to conduct and coordinate a research program on hormone disruption. The bill was referred to the Subcommittee on Research on May 15. This bill mentions the USGS' considerable experience assessing the occurrence of chemicals in the environment, ecological health, and the hazards to wildlife health and associated human health posed by chemicals in the environment, as a result of monitoring by the USGS of the Nation's water resources and wildlife disease, and research by the USGS on the effects of chemicals on wildlife. The bill calls for $500,000,000 for NIEHS for the 5-fiscal-year period beginning with fiscal year 2003. The Director of NIEHS may transfer funds to other Federal agencies to carry out the Director's responsibilities outlined in the bill.
Some of the language in HR 4709 which mentions USGS includes the following:
"...The Director of the Institute (NIEHS) shall establish within the Institute a comprehensive program to--
(A) conduct research on the impact of chemicals that affect human health through disruption of the hormone systems;
(B) conduct research on the occurrence of hormone disrupting chemicals in the environment and their effects on ecological and wildlife health, in cooperation with the United States Geological Survey (referred to in this section as the `USGS');
(C) coordinate the design of a multi-agency research initiative on hormone disruption;
(D) coordinate research on hormone disruption in the United States with such research conducted in other nations; ... The Director of the Institute (NIEHS) shall have principal responsibility, in consultation with the Director of the USGS, for conducting and coordinating research on the effects of hormone disrupting chemicals on human health and the environment."
May 2, 2002
WelcomeWelcome to the first edition of the Survey’s electronic newsletter, dedicated to dissemination of current information on USGS health-related activities. The newsletter is intended to be an internal USGS document that will foster a sense of community among the many scientists and managers concerned with health-related issues. In future newsletters we will highlight some of the many exciting health-related research projects being conducted by USGS scientists. Epidemioecology (see box) is growing rapidly within the USGS and within the geoscience community, as is evidenced by the signs of progress listed below. We are making visible progress in catching the attention of the public health community and fully expect that interest in epidemioecology will continue to expand in the foreseeable future. USGS Director Chip Groat sent a very clear message of encouragement and support in his FY03 Director’s Annual Guidance. He said: “We should look beyond what we are now describing as our human-health related activities to be sure we have identified all relevant efforts, and we should identify opportunities, within existing funds, to expand the dimensions of this program.” Looking further to the future, the Director recommends a “Modest expansion of our human health initiative linked clearly to our core capabilities in environmental analysis and geospatial data systems.” Clearly, there is tremendous potential for the USGS to contrute to solutions for a wide range of environmental health problems. We hope that the Epidemioecology News may help with this effort by facilitating communications. |
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