The U.S. Geological Survey's Environmental Health Newsletter - Recent Research Edition

Volume 16
Issue 1
February 2020
Recent Research

This edition of the GeoHEALTH—USGS Newsletter features recent research from the USGS's Toxic Substances Hydrology and Contaminant Biology Programs



Mixtures of Algal Toxins Present Prior to and After Formation of Visible Algal Blooms—Science to Inform the Timing of Algal Toxin Exposure

Cyanobacteria with toxin-producing potential, genes indicating an ability for toxin synthesis, or cyanotoxins were present before and after formation of a visible algal bloom in Kabetogama Lake, a popular recreation area in Voyageurs National Park that lies along the border of Minnesota and Canada. The temporal patterns observed in this study indicate that sampling only when there is a visible...

Aerial view of a wastewater-treatment plant

Refined Model Provides a Screening Tool to Understand Exposure to Contaminants from Incidental Wastewater Reuse

Refinement of the existing national-scale “de facto reuse incidence in our nation’s consumable supply” (DRINCS) model, complemented by field measurements, provides a screening tool to understand human and wildlife exposure to toxicants and pathogens associated with the incidental reuse of treated wastewater in the Shenandoah River watershed. The model results can be accessed in a companion...

Brown Bullhead from the Ashtabula River Illustrating the External Tumors Observed

Prevalence of Malignant Melanoma in Brown Bullhead from Lake Memphremagog—Linkages to Contaminant Exposure and Implications for Fish Population Health are Currently Unknown

Raised black lesions observed in 30 percent of the brown bullhead collected from two sites in Lake Memphremagog from 2014 through 2017 were identified microscopically as malignant melanoma. Malignant melanoma in freshwater fishes has been reported before, but this cancer occurrence cluster is raising questions about the cause of the tumors and the implications for the long-term health of fish...

Image: Zebra Mussels

Food Web Changes Dampen Expected Reductions in Lake Trout Mercury Levels in Lake Michigan—Invasive Species Play Major Role

Combined analyses of mercury, nitrogen, and carbon isotopes in archived lake trout (Salvelinus namaycush) tissues and sediment cores in Lake Michigan from 1978 to 2012 indicated that lake trout mercury concentrations mirrored declines in mercury sources prior to the arrival of invasive species that changed mercury transfer through the food and dampened the expected decreases in mercury...

Water flows from a stormwater outfall

Ongoing Research to Characterize the Complexity of Chemical Mixtures in Water Resources—Urban Stormwater

A multiagency reconnaissance study of chemicals in urban stormwater, sampled from pipes or ditches during 50 runoff events at 21 sites in 17 states across the United States, demonstrated that stormwater runoff contains complex mixtures of chemicals including polycyclic aromatic hydrocarbons, pesticides, and pharmaceuticals that are indicative of multiple potential sources in the watershed.

Largemouth bass at the USFWS Mountain-Prairie Aquarium

Mercury Isotope Ratios used to Determine Sources of Mercury to Fish in Northeast U.S. Streams

Mercury isotope analyses were used to distinguish different sources of mercury to fish in 23 streams along a forested-rural to urban-industrial land-use gradient in the Northeast United States. The use of mercury isotope measurements in fish tissue allow for distinguishing different sources of mercury that are bioaccumulating into the food web. Mercury isotope signatures in fish in forested...

Scientist holding a yellow warbler

Science to Help Understand Exposure and Toxicological Effects of Environmental Mercury to Representative Birds

Exposure and toxicity of environmental mercury to birds can be enhanced or lessened due to the available sources and forms of mercury and other species dependent factors such as life stage, migratory patterns, foraging and nesting behaviors, transfer of mercury from mothers to eggs, and sex. For example, mercury exposure can lead to sublethal toxicological effects that can influence parental...

Smallmouth Bass

Intersex in Male Smallmouth Bass in the Missisquoi River in Vermont: Understanding Factors that Can Lead to Endocrine Disruption in Field Settings

The presence of testicular oocytes (intersex) in male smallmouth bass (Micropterus dolomieu) in the Missisquoi River in Vermont varied over the period of the study and was not related to concentrations of known endocrine disrupting chemicals in the River. Although previous studies have shown linkages between endocrine disrupting chemical exposures and intersex in fish, these results...

Collecting Surface Water Samples in the Rabenberg Waterfowl Protection Area

Amphibians Exposed to Oil and Gas Co-Produced Wastewaters: Differentiating the Actual and the Perceived Inorganic Contaminant Hazards — Prairie Pothole Region

Chloride and metals in oil and gas co-produced wastewaters (often referred to as brines) are commonly perceived as contaminant hazards for biota. Amphibian abundance in the Prairie Pothole Region affected by historic oil and gas co-produced wastewaters was lower in wetlands with high concentrations of chloride indicating an actual contaminant hazard. Metals detected in sediments and amphibian...

Two small birds at a bird house

No Adverse Reproductive Effects Observed in Tree Swallows Exposed to Perfluoroalkyl Substances in Clarks Marsh, Michigan

Perfluoroalkyl substance (PFAS) concentrations in tree swallows (Tachycineta bicolor) breeding at Clarks Marsh near a decommissioned U.S. Air Force base in Michigan were among the highest concentrations ever documented in birds indicating significant PFAS exposures.   In contrast to previous studies where reproductive impairment was documented at lower PFAS exposure, there were no...

Image: Black-Crowned Night-Heron (Nycticorax nycticorax)

Sublethal Effects of Contaminants in Aquatic Food Webs—Research Challenges and Considerations for Future Studies

U.S. Geological Survey (USGS) and academic scientists partnered to identify challenges and provide considerations for future scientific study designs to advance our understanding of the often subtle sublethal effects of contaminants on individuals, populations, communities, and entire aquatic food webs. 

Japanese quail (Coturnix japonica)

No Evidence of Toxicity to Birds Ingesting Neonicotinoid-Coated Wheat Seeds During Controlled Laboratory Study

Scientists determined what happens to the neonicotinoid insecticide, imidacloprid, on coated wheat seeds once ingested by Japanese quail (Coturnix japonica)—a model species for free-range, seed-eating, upland game birds. Imidacloprid was found to be rapidly adsorbed, metabolized, and excreted, and resulted in no overt signs of toxicity during a controlled laboratory study.

Mountain Sheep Spring, Arizona

Uranium in Springs Sampled Near the Grand Canyon is Likely from Natural Sources

Scientists measured nine naturally occurring elements including uranium at 37 spring sites in the Grand Canyon area to establish baseline conditions and to understand the sources of uranium to local springs. Scientists found relatively greater concentrations of uranium at 6 of the 37 springs. A comprehensive geochemical analysis coupled with an understanding of the flow patterns in the area...

Blobs of spilled element mercury (Hg)

Roadmap to Understand Factors Influencing Mercury Exposure and Adverse Health Effects

In a comprehensive overview, scientists explain that human and wildlife exposure and toxicological responses to mercury are dependent on factors that operate across global, individual, and molecular scales. They provide a roadmap for unified research to facilitate a better understanding of human and wildlife health risks from mercury exposure.


USGS scientist sampling tap water from a public water supply

Pilot Study Provides Information on Contaminant Exposure from Tap Water at Residential and Workplace Sites in the United States

The U.S. Geological Survey (USGS), in collaboration with National Institutes of Health, U.S. Environmental Protection Agency, and academia, completed a pilot study to provide information on contaminant exposure from tap water at 26 locations including public and private supplies. Public-supply tap water generally met enforceable standards for those compounds with standards. Samples consisted...

USGS scientists collecting oil from wells

Variability in Composition of an Oil Spill after more than 30 Years of Natural Attenuation

More than thirty years after an oil spill, hydrocarbons measured in groundwater near Bemidji, Minnesota, have been depleted between 25 and 85 percent. However, some components have remained for many decades and some are expected to remain longer indicating that natural attenuation is an effective but slow process. Compounds that are sufficiently soluble and resistant to biodegradation provide...

Clean drinking water

Per- and Polyfluoroalkyl Substances (PFASs) detected in Source Waters and Treated Public Water Supplies

This study, which measured 17 per- and polyfuoroalkyl substances (PFASs) in source and treated public water supplies from 25 drinking water facilities as part of a broader study of contaminants in drinking water across the United States, reports that PFASs were detected in all source water and public water supply samples collected. One sample exceeded the current U.S. Environmental...

Digitally-colorized transmission electron microscopic image of intact rotavirus

Novel Approach Improves Understanding of Virus Occurrence in Drinking Water

Waterborne viruses, one of the leading causes of gastrointestinal illnesses, were measured in United States drinking water sources and finished water. Scientists used a combination of measurement and statistical techniques to overcome limitations to quantifying these viruses, thus offering an enhanced method for virus monitoring.

two newly-hatched osprey chicks in the nest

Long-term Studies Examine Contaminant Exposure and Reproduction of Ospreys Nesting in Two Large United States Estuaries

In a series of studies from 2010 to 2018, U.S. Geological Survey (USGS) scientists detected low levels of legacy contaminants and pharmaceuticals in osprey (Pandion haliaetus) and their food chain within the Chesapeake and Delaware River estuaries. Osprey reproductive success increased during the same period and was determined to be adequate to sustain a stable population in both...

A colony of cyanobacteria cells from Lake Okeechobee, Florida

Understanding Drivers of Cyanotoxin Production in the Lake Okeechobee Waterway

The U.S. Geological Survey (USGS) and other researchers combined field and laboratory approaches in two studies to understand the factors that drive cyanobacterial bloom development and associated cyanotoxin production in Lake Okeechobee, the St. Lucie River and Estuary, and the Indian River Lagoon in response to the large-scale Lake Okeechobee cyanobacteria bloom in 2016.

Close up of a Northern Leopard frog (Lithobates pipiens) in a wetland

Unique Methods Used to Understand Frog Exposure to Pesticides in Agricultural Settings

Adult frog exposure to pesticides in aquatic and terrestrial habitats was quantified using a novel combination of radio telemetry and passive sampling techniques to better understand factors affecting frog health and survival in agricultural landscapes.

Scientist preparing samples in a laboratory

Systematic Approach to Understanding Tree Swallow Health in the Great Lakes Region—Science to Inform Restoration

Four papers by U.S. Geological Survey (USGS) scientists document tree swallow (Tachycineta bicolor) chemical exposure, physiological responses, and reproductive success in the Great Lakes region. These studies were designed to understand if there are health threats to swallows from contaminant exposure, and to provide resource managers with information about the actual as opposed to...


The GeoHEALTH–USGS newsletter has been published 2 to 4 times per year since 2006, and provides a publicly accessible summary of USGS science activities pertinent to the health of fish, wildlife, domestic animals, and humans.

Michael J. Focazio, Editor
Kathy E. Lee, Managing Editor
Victoria G. Christensen, Associate Editor
Gregory K. Boughton, Coordinating Editor
Stephanee R. Walker, Copy Editor

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