Exposure Pathways

U.S. Geological Survey (USGS) scientists have developed a tool that can be used by practitioners to help interpret injury to birds caused by methylmercury contamination. This tool was developed from a comprehensive review of 168 studies and summarizing data on the effects of methylmercury on birds.

About the Research The Microbial Biogeochemistry Laboratory Core Technology Team (CTT) as part of the Environmental Health Program focuses on environmental questions in aquatic systems (sediment and water) involving the linkages between major biogeochemical cycles (those involving carbon, sulfur, iron and nitrogen) and those associated with contaminants of concern.

About the Research The Geospatial Analyses and Applications Core Technology Team (CTT) as part of the Environmental Health Program collaborates with teams across USGS to develop and apply geospatial analytical methods to answer broad-scale questions about source-sink and cause-effect relationships between contaminants and vulnerable communities.

The team studies toxicants and pathogens in water resources from their sources, through watersheds, aquifers, and infrastructure to human and wildlife exposures. That information is used to develop decision tools that protect human and wildlife health.

Increasing scientific and public awareness of the widespread distribution of per- and poly-fluoroalkyl substances (PFAS) in U.S. drinking-water supplies, aquatic and terrestrial ecosystems, wildlife, and humans has raised many public health and resource management questions that U.S. Geological Survey's (USGS) science can inform. The USGS Environmental Health Program's PFAS Integrated Science Team...

Field study in California describes the potential for pollinator-attractive field borders in agricultural areas to become a pesticide exposure pathway to bees through soil, air, and plants.

USGS recently (2022) released a strategic vision document that identifies science gaps and opportunities for per- and polyfluoroalkyl substances (PFAS) monitoring, assessment, and research activities (sampling protocols and analytical methods, environmental sources and source apportionment, environmental occurrence, environmental fate and transport, human and wildlife exposure routes...

Per- and poly fl uoroalkyl substances (PFAS) were detected in streams within agricultural areas (an often-unmeasured landscape) across Iowa. The data from this study provide one resource to understand the extent of PFAS concentrations in water resources from diverse landscapes throughout the United States.

The team develops advanced methods to study factors driving algal toxin production, how and where wildlife or humans are exposed to toxins, and ecotoxicology. That information is used to develop decision tools to understand if ​toxin exposure leads to adverse health effects in order to protect human and wildlife health.

A group of scientists investigated per- and polyfluoroalkyl substances (PFAS) in watersheds on Cape Cod and identified a unique signature for aqueous film forming foams (AFFF) from legacy firefighting and fire training. A combination of statistical modeling and laboratory measurements indicates that unidentified organofluorine constitutes a large fraction of PFAS in the river systems that...

Groundwater discharge zones are important spawning areas for fish because they provide a thermally stable habitat. Research at three streams in the Chesapeake Bay Watershed with areas of focused groundwater discharge revealed that groundwater also is a source of phytoestrogens and herbicides that could result in fish exposure during sensitive life stages.

U.S. Geological Survey scientists and their partners utilize laboratory and field studies and existing information to improve understanding of anticoagulant rodenticide exposure and effects to wild birds.