Exposure Pathways

The US Geological Survey (USGS) and collaborators at the University of Wisconsin-Madison have developed a new tool for attributing (fingerprinting) mercury sources to the Great Lakes. This new fingerprinting tool helps resource managers understand which mitigation strategies will be most effective for reducing mercury loading and exposure to fish and wildlife.

The occurrence of complex mixtures of prescription pharmaceuticals in streams and rivers around the globe has raised concerns about potential unintended adverse effects on aquatic organisms. The deleterious effects (for example, alteration of fish behavior) observed in this study confirm that effluents containing pharmaceuticals can adversely affect fish in ways that are central to sustaining...

New scientific research from the U.S. Geological Survey (USGS) details how landfill leachate, disposed from landfills to environmental pathways, is host to numerous contaminants of emerging concern (CECs).

A recent reconnaissance study by the U.S. Geological Survey (USGS) demonstrates the first observed occurrence of pesticides, including neonicotinoid insecticides, in wild-caught native bees. The results indicate that native bees collected in an agricultural landscape are exposed to multiple pesticides including insecticides, fungicides, and herbicides. This reconnaissance study is the first step...

Neonicotinoid insecticides (neonicotinoids) were present in a little more than half of the streams sampled across the United States and Puerto Rico, according to a new U.S. Geological Survey (USGS) study. This is the first national-scale study of the presence of neonicotinoids in urban and agricultural land use settings across the Nation and was completed as part of ongoing USGS investigations of...

U.S. Geological Survey (USGS) scientists determined that endocrine disrupting chemicals (EDCs) were present in wastewater treatment plant (WWTP) effluent, water, and fish tissue in urban waterways in the Great Lakes and upper Mississippi River Regions (Indiana, Illinois, Michigan, Minnesota, and Ohio) during 1999 through 2009.

The U.S. Geological Survey (USGS) and the U.S. Environmental Protection Agency (EPA) are collaborating on a field-based study of chemical mixture composition and environmental effects in stream waters affected by a wide range of human activities and contaminant sources.

Pharmaceuticals, hormones, personal care products, and other contaminants of concern associated with everyday household activities were found in adjacent shallow groundwater near two septic system networks in New York (NY) and New England (NE). Factors influencing movement to shallow groundwater and the types of chemicals found include population served by a septic system, site conditions such as...

A new USGS report, Mercury in the Nation's Streams—Levels, Trends, and Implications, presents a comprehensive assessment of mercury contamination in streams across the United States. It highlights the importance of environmental processes, monitoring, and control strategies for understanding and reducing stream mercury levels. This report summarizes selected stream studies conducted by the U.S...

U.S. Geological Survey (USGS) scientists used a mass–balance solute–transport model to enhance an understanding of factors affecting chlorinated ethene (CE) concentrations in a public supply well. They found that long–term simulated and measured CEconcentrations were affected by dense nonaqueous phase liquid (DNAPL) volume, composition, and by the bioavailability of organic carbon that drives...

U.S. Geological Survey (USGS) scientists studying a midwestern stream conclude that pharmaceuticals and other contaminants in treated wastewater effluent discharged to the stream are transported into adjacent shallow groundwater. Other mobile chemicals found in wastewater are expected to have similar fates.

Landfill leachate contains a variety of chemicals that reflect our daily activities, U.S. Geological Survey (USGS) scientists concluded as a result of a nationwide study. Landfills are a common disposal mechanism for our Nation's solid waste from residential, commercial, and industrial sources. The scientists found that pharmaceuticals, personal-care products, and other contaminants of emerging...