Exposure Pathways

A U.S. Geological Survey (USGS) study elucidates the influence of animal type and environmental variables on bacterial pathogen occurrence in streams under typical watershed conditions.

Potential long-term contaminant threats resulting from compromised infrastructure, beach erosion, and sediment disturbance were evaluated in the coastal environments of New Jersey and New York in the aftermath of Hurricane Sandy.

Scientists conducted laboratory experiments on levonorgestrel (a synthetic progestin) and observed differential effects to males (reproductive behavior) and females (masculinization) of eastern mosquitofish ( Gambusia holbrooki).

Newly published study provides new evidence of the widespread occurrence of cyanotoxins in lakes and reservoirs of the United States and offers new insights into measures used for assessing potential recreational health risks.

Iodinated disinfection byproducts were found at stream locations downstream from treated discharge from wastewater treatment plants that receive dairy waste and in the wastewaters directly from dairy facilities.

Evidence indicating the presence of wastewaters from unconventional oil and gas (UOG) production was found in surface waters and surficial sediments near an UOG disposal facility in West Virginia.

U.S. Geological Survey (USGS) scientists determined that the colmation layer (top 25 centimeters of lake sediments) was highly effective in removing cyanobacteria, viruses, and dissolved organic carbon during water passage through the lake bottom to aquifer sediments.

U.S. Geological Survey (USGS) scientists studying two subsurface crude-oil spill sites in Minnesota measured concentrations of oil breakdown products (metabolites) at greater concentrations than parent compound concentrations.

U.S. Geological Survey (USGS) scientists developed an approach and collected baseline data to quantitatively assess offsite migration of mine-related contaminants and to identify critical contaminant exposure pathways that could result from uranium mining activities in the Grand Canyon region.

Recent findings from a consortium of university, State, and U.S. Geological Survey (USGS) scientists indicate that declining atmospheric concentrations of mercury (Hg) can be explained by the phaseout of mercury in many commercial products and by reduced emissions from utilities over the past two decades.

Four Federal agencies, including the U.S. Geological Survey (USGS), are collaborating to transform satellite data into information managers can use to protect ecological and human health from freshwater contaminated by harmful algal blooms.

Experimental field research simulating hydrocarbon spills by researchers from the U.S. Geological Survey (USGS), Virginia Tech, and the University of St. Thomas showed that mixed ethanol and petroleum-based fuels increased the rate by which arsenic and other natural trace elements are released from aquifer sediments to groundwater when compared to petroleum-based fuels alone.