USGS at Society of Environmental Toxicology and Chemistry

From pharmaceuticals in groundwater to mercury in high US mountains

The 27th Annual Meeting of the Society of Environmental Toxicology and Chemistry (SETAC) is being held November 5-9, 2006, at the Palais de Congrès in Montréal, Québec, Canada. Additional information about the conference can be found online at http://montreal.setac.org/home.asp While the conference is occurring, please contact Catherine Puckett for information about specific presentations.

A Happy Medium? Antidepressants in Aquatic Systems: Wastewater treatment plants do a remarkable job at removing the bulk of chemicals from the waste stream. But recent USGS studies have shown that a wide range of pharmaceuticals and other human-caused waste compounds remain despite wastewater treatment and are discharged to receiving waters across North America. Antidepressants are a commonly used class of pharmaceuticals whose pharmacological effects may extend beyond humans to aquatic organisms present in surface water systems that receive treated wastewater discharge. Yet few methods exist to detect antidepressants in the environment, and their effects on aquatic organisms are only beginning to be understood. Recently, USGS researchers developed a method to study the distribution and fate of antidepressants and their breakdown products in aquatic environments, including municipal wastewater and surface water. Venlafaxine (Effexor) was the predominant antidepressant researchers found in wastewater and river-water samples from Colorado, Iowa, and Minnesota, though other antidepressants were found as well. Typical concentrations of individual antidepressants ranged from a few nanograms per liter to thousands of nanograms per liter (for Venalfaxine) in wastewater. This indicates that wastewater is a point source of antidepressants into the environment, at concentrations that may impact aquatic life. For more information, please contact Edward T. Furlong, USGS, at efurlong@usgs.gov or 303-236-3941; or Melissa Schultz, College of Wooster, Wooster, OH at mschultz@wooster.edu or 330-263-2645. SETAC presentation is Monday, Nov. 6, 8:20 a.m., Room 517A, Palais de Congrès.

Pharmaceuticals in Long Island's Groundwater: Pharmaceuticals can infiltrate groundwater systems in areas susceptible to wastewater contamination. In studies by Stony Brook University and the U.S. Geological Survey of ground-water wells in Suffolk County, Long Island, NY, near permitted wastewater treatment facilities discharging to ground water, scientists detected pharmaceuticals in concentrations generally 1-200 ng/L (parts per trillion).These vanishingly small concentrations are several orders of magnitude below the concentrations where any effects have been observed or predicted for the compounds measured in this study. Acetaminophen, caffeine, carbamazepine (anti-epileptic), cotinine (human metabolite of nicotine), paraxanthine (human metabolite of caffeine), and sulfamethoxazole (antibiotic) were found most often in both studies. However compounds were more frequently detected in the shallower wells. These occurrences, and laboratory studies, suggest that of these compounds, caffeine, carbamazepine, paraxanthine, and sulfamethoxazole are more persistent in groundwater and have the most potential for transport in the subsurface. For more information, contact Mark J. Benotti at mbenotti@usgs.gov or 631-736-0783 x126. SETAC presentation is Thursday, Nov. 9, 4:50 p.m., Room 516AB, Palais de Congrès.

After the Hurricanes – The Contaminants Left Behind in New Orleans: USGS researchers measured numerous semivolatile organic compounds in street floodwater mud and Lake Pontchartrain sediment samples collected in September and October 2005 after the levee breaches caused by Hurricane Katrina and subsequent flooding from Hurricane Rita. These compounds include compounds organochlorine pesticides, PCBs, PAHs, current-use pesticides, anthropogenic indicator compounds (AICs), and pharmaceuticals (in the mud only). Contaminant concentrations in street mud varied substantially and for some – including PAHs, some AICs, and four termiticides – were highest at several sites near downtown New Orleans when compared with other locations (Chalmette, Ninth Ward, Slidell, Rigolets). USGS researchers found that the highest concentrations of urban-related compounds (such as chlordane and PAHs) in lakebed sediments exceeded average concentrations in U.S. urban lakes and sediment quality guidelines, but were not markedly dissimilar to historical values or to those reported from other urban areas. The highest concentrations were limited to within a few hundred meters of the 17th Street Canal outlet into the lake. This research suggests that the impacts of the hurricanes on the sediment history of Lake Pontchartrain are most likely transitory and confined to a relatively small geographic region. For more information, contact W. T. Foreman at wforeman@usgs.gov or 303-236-3942. SETAC presentation is on Thursday, Nov. 9, 10:40 a.m., Room 516C, Palais de Congrès.

Rocky Mountain High -- Mercury in Cold Environments of the Western United States: Atmospheric deposition of mercury in remote areas in the Western United States is sufficient to pose a risk to human and ecosystem health at sites favorable for methylation, a process in which mercury in the environment is converted into a highly toxic form that accumulates in organisms and is amplified up the food chain. USGS researchers and partners measured mercury in snowpack samples during 2003-2005 as part of the National Park Service Western Airborne Contaminants Assessment Project. Eight high-altitude, high-latitude sites were selected for study in or near national parks in Colorado, Montana, California, Oregon, and Alaska. Mercury levels were lowest in the North Cascades, highest in the Rocky Mountains, and were related to the amount of particulate carbon in the snow, with both found at higher levels in forested sites than in open meadows. Seasonal variations were lowest in Denali National Park and highest in Olympic National Park. Mercury concentrations were higher during the warm season than the snow season. Total annual fluxes of mercury were as high as 10 ?g m-2 at some sites in the Rocky Mountains, which receive mercury deposition equal to that in the Upper Midwest or Northeast. Global and regional sources of mercury emissions contribute to its deposition, with regional sources likely contributing more in the Rocky Mountains, where there are more upwind sources of emissions. For more information, contact Don Campbell at Donald.Campbell@usgs.gov or 303-236-4882, ext. 298. SETAC presentation is on Thursday, Nov. 9, 8 a.m.- 7 p.m., Exhibit Hall, Palais de Congrès. Poster #934.

Contaminants Lower Reproductive Health of Gila River Fish: Downstream of Phoenix, southern Arizona's Gila River is primarily recharged by irrigation return water, storm water, and wastewater treatment plant effluent, and fish and aquatic invertebrate habitats are degraded. Largemouth bass, common carp and channel catfish from the Gila had elevated levels of organochlorine pesticides, many of which have been associated with estrogen-like effects in fish. Reproductive biomarkers, including gonad size and hormone concentrations, were notably different in fish from the Gila River when compared to fish from the Colorado River, indicating that organochlorine contaminants may be affecting the reproductive health of fish populations in the Gila River downstream of Phoenix. For more information, contact Jo Ellen Hinck at jhink@usgs.gov or 573-876-1808. SETAC presentation is on Thursday, Nov. 9, 2:30 p.m., Room 517B, Palais de Congrès.

Aquatic Herbicides May Benefit Invasive Aquatic Species: Aquatic plants are frequently exposed to low-levels of agricultural herbicides at concentrations less than those known to cause adverse effects in the laboratory. Laboratory studies have shown that low levels of herbicide exposure can actually increase growth rates of aquatic plants due to physiological stress adaptations. Scientists from the U.S. Geological Survey and the University of Manitoba studied whether low levels of herbicides in aquatic systems may actually aid non-native invasive aquatic plants, allowing them to out-compete or displace more desirable native aquatic plant species. Researchers studied the effects of atrazine herbicide on both native and non-native, invasive aquatic plants in experimental ponds over a period of 42 days. Results confirmed that lower levels of atrazine could actually stimulate growth of some invasive species. Some invasive aquatic plant species were less sensitive to atrazine than a common native aquatic plant species. Although the invasive species did not totally displace the native species, the results indicate that some herbicides may have the unintended consequence of benefiting non-native invasive species that may compete with native aquatic plant species. Aquatic plants are critical components of aquatic ecosystems by providing habitat and energy sources for many fish and invertebrates. For more information, contact James F. Fairchild at jfairchild@usgs.gov or 573-876-1871. SETAC presentation is on Wednesday, Nov. 8, 10:20 a.m., Room 516AB, Palais de Congrès.

Wastewater Issues Get Wormy: Recent research indicates that earthworms may be an important initial step by which organic contaminants could enter the terrestrial food web. Wastewater treatment plants process millions of gallons of mixed solid and liquid human waste daily, returning treated effluent to surface and ground water and disposing of the residual sludge. Roughly half of the many thousands of dry tons of treated sludge (usually referred to as biosolids) generated annually in the U.S. are applied to agricultural soils as a nutrient-rich soil amendment. Recent USGS research has identified a wide variety of organic contaminants (such as disinfectants, pharmaceuticals, synthetic fragrances, and plasticizers) that can be present in biosolids, often in concentrations tens to thousands of times higher than found in treated liquid waste. One concern related to the practice of land application of biosolids is whether any of these organic contaminants find their way into soil-dwelling organisms. To address this concern, USGS and Eastern Washington University scientists collaborated on a study of earthworms collected from agricultural soils in the Midwest and Western United States that had been exposed to land-applied biosolids. The samples were analyzed for a diverse array of pharmaceuticals and other organic contaminants (77 target compounds were measured). Soil and earthworm samples were collected from select agricultural fields early and late in the growing season. Thirty-one compounds including triclosan (household disinfectant), several fragrances, caffeine, and fluoxetine (the antidepressant Prozac) were detected in earthworms from biosolid-applied fields, with tissue concentrations ranging from 100's to 1000's of micrograms per kilogram (parts per billion). These results demonstrate that earthworms can accumulate a range of these chemically diverse organic contaminants within their tissues, and may be an important initial step by which these compounds could enter the terrestrial food web. For more information contact Ed Furlong, USGS, at efurlong@usgs.gov or 303-236-3941, and Chad Kinney, Eastern Washington University, at ckinney@mail.ewu.edu or 509-359-7932. SETAC presentation is on Thursday, Nov. 9, 4:10 p.m., Room 516 AB, Palais de Congrès.

Toxicity Tests for Endangered Mussels: The United States is home to more mussel species than any other country in the world. Despite the diversity of mussels found in the country, no other widespread group of animals in North America is as imperiled or has faced as many extinctions. The abundance and variety of mussels have declined sharply over the past century, but the cause of mussel decline is not well understood. Researchers at the USGS-Columbia Environmental Research Center, in cooperation with other government agencies, academia, and private industry, are developing the first standardized toxicity tests using several life stages of freshwater mussels to assess the effects that pollution may have on these declines. Mussels are filter feeders that readily accumulate toxins. Results of this ground-breaking work indicate that water quality criteria for individual chemicals established for the protection of aquatic organisms may not be adequately protective of sensitive stages of freshwater mussels. For more information, contact Ning Wang, nwang@usgs.gov or 573-441-2946. SETAC presentation is on Thursday, Nov. 9, 8 a.m.-7 p.m., Exhibit Hall, Palais de Congrès. Poster # 1056

Toxic Tango: Interactions of Mercury and Selenium on Bird Embryos: Mercury and selenium are common environmental contaminants that sometimes occur together at elevated levels in bird eggs. Both have been associated with reproductive impairment in birds, in particular by embryonic death and deformities. Although a lot is known about the toxicity of these two contaminants by themselves in eggs, little is known about potential toxic interactions when they occur in the same egg. USGS research indicates that combining the contaminants had a worse effect on mallard embryos than either one did separately. Follow-up studies, however, revealed that combined effects of these two contaminants may vary by species and exposure amount. For more information, contact Gary Heinz at gary_heinz@usgs.gov or 301-497-5711. The SETAC presentation is on Wednesday, Nov. 8, 10 a.m., Room 511AD, Palais de Congrès.

Contaminants Affect Over-Winter Survival of Swallows: The effects of chronic contaminant exposure on over-winter survival of birds are largely unknown. These studies are difficult to carry out because suitable bird species may not occur in contaminated locations, there may be insufficient number of breeding birds, they may be difficult to capture, or the species may to too long-lived to study within a reasonable time. Tree swallows overcome many of these research problems. Large numbers of breeding birds can be attracted to a site because they will readily nest in man-made nest boxes. They are also relatively easy to capture, return to the same breeding site year after year, and are short lived. The Housatonic River in western Massachusetts is extremely contaminated with polychlorinated biphenyls (PCBs) and PCB concentrations in swallow eggs are associated with decreased reproductive success. USGS researchers studied the effect on over-winter survival of chronic exposure to PCBs for 5 years on the Housatonic River to determine if adult swallow survival was reduced in this highly contaminated environment. Researchers found that annual over-winter survival was reduced significantly by about 5 percent in females that nest at the most contaminated sites. For more information contact Christine M. Custer, ccuster@usgs.gov or 608-781-6247. SETAC presentation is on Monday, Nov. 6, 2:10 p.m., Room 517 B, Palais de Congrès.

Fungicides: Analysis, Fate, and Toxicity: The recent spread of Asian soybean rust to North America has increased interest in fungicides to combat this scourge. Despite decades of agricultural and urban use, relatively little data are available on the fate and effects of fungicides in the aquatic environment. One of the most used fungicides in the United States, chlorothalonil, has been used for over 50 years for a variety of applications. Other fungicides (azoxystrobin, myclobutanil, propiconazole, pyraclostrobin, and tebuconazole) have been recently registered for treatment of soybean rust and are rapidly increasing in use. Some of these fungicides are highly toxic to fish and other aquatic life. Fungicides are often not included in monitoring programs, although fungicides and their degradates have been detected in water, sediments, air and rainfall at concentrations that can cause adverse effects to aquatic organisms. Effective monitoring of fungicide concentrations is required to understand if increasing use will result in increasing stream concentrations. The focus of this session will range from older fungicides such as chlorothalonil to newer fungicides such as the triazoles and strobilurins. Topics will include analysis of fungicides and their degradates, environmental occurrence, degradation pathways, modes of action, and toxicity to aquatic organisms. For more information, contact Kathryn Kuivila at kkuivila@usgs.gov or 916-278-3054. The symposium, which is sponsored by the U.S. Geological Survey and Mississippi State Chemical Laboratory, will take place on Wednesday, Nov. 8, in room 510 BD, Palais de Congrès, from 8:00 - 11:40 a.m.

How Much is Too Much? Mercury Thresholds for Common Loon Eggs: Assessing the ecological risk of mercury exposure to fish-eating wildlife is a priority issue for federal and state resource management agencies. Atmospheric mercury deposition has increased due to industrial activities exposing fish-eating wildlife populations in New England, coastal Atlantic states, the Southeast and the Upper Midwest to elevated mercury in their prey. The USGS, Wisconsin Department of Natural Resources, and the University of Wisconsin have conducted research to generate a scientifically defensible common loon/mercury risk assessment model. The work focused on the common loon because this species is sensitive to the toxic effects of mercury and has the greatest risk of mercury exposure among wildlife species on inland (non-marine) North American aquatic systems. A critical component of the model is determining the level of mercury in loon eggs that poses a population level risk. In 2005 and 2006, researchers conducted a study to better characterize methylmercury exposure in eggs of Wisconsin common loons and to determine the level of exposure in eggs that reduces fitness and survival of loon embryos and resultant chicks. Blood mercury levels in a sample of Wisconsin loon chicks indicated mercury exposure in some chicks rivaled that of adult birds during the breeding season. Blood mercury concentrations rapidly declined in growing chicks, such that by six weeks of age blood mercury levels were about 6 percent of levels at hatch. Reduced embryo survival was evident at an egg content concentration of mercury that is representative of what is often found on low pH lakes in northern Wisconsin, although sample sizes are small. For more information, contact Kevin Kenow at kkenow@usgs.gov or 608-781-6278. SETAC presentation is on Wednesday Nov. 8 at 8:40 a.m., Room 511 AD, Palais de Congrès.

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Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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