Toxic Substances Hydrology Program

Featured Science Activities

Our science is summarized in a series of feature articles that highlight recent U.S. Geological Survey (USGS) environmental health science activities. They are short summaries of peer-reviewed journal articles and USGS reports co-authored by our specialized teams of scientists.

Filter Total Items: 100
Date published: November 8, 2019
Status: Completed

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 sources in the watershed.

Date published: October 11, 2019
Status: Completed

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 Northeastern 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...

Date published: October 4, 2019
Status: Completed

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...

Contacts: Josh T Ackerman
Date published: October 3, 2019
Status: Completed

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...

Date published: October 2, 2019
Status: Completed

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...

Contacts: Kelly Smalling
Date published: October 1, 2019
Status: Completed

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...

Date published: May 7, 2019
Status: Active

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. 

Contacts: Kelly Smalling
Date published: April 22, 2019
Status: Active

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.

Date published: February 25, 2019
Status: Completed

Uranium in Springs Sampled Near the Grand Canyon 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...

Date published: February 25, 2019
Status: Completed

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...

Date published: February 8, 2019
Status: Completed

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...

Date published: February 5, 2019
Status: Active

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...

Contacts: Edward Furlong, Dana W Kolpin, Susan T. Glassmeyer