Exposure Pathways

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.

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.

The team is determining the movement and behavior of per- and poly-fluoroalkyl substances (PFAS) from their sources in the environment, as they move through exposure pathways in ecosystems including watersheds and aquifers, their incorporation into food webs, and molecular to population scale effects on fish and wildlife. These studies are accomplished at a variety of spatial scales from regional...

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.

A web-based application tool utilizing satellite data—CyANWeb—developed through collaborative interagency efforts was released as part of the Cyanobacteria Assessment Network (CyAN) to help Federal, State, Tribal, and local partners identify when cyanobacterial blooms may be forming. Available through a web browser or as an application, the tool can access, download, and provide data to notify...

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.

The Immunomodulation Integrated Science Team focuses on contaminant and pathogen exposures in the environment that might influence the immune systems of wildlife and the connection to their shared environment with humans. In collaboration with public-health officials, the Team also addresses potential human-health risks stemming from similar exposures. If actual risks are identified, this Team...

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...

The Ecologically-Driven Exposure Pathways Integrated Science Team identifies how ecological pathways and physiological processes within a single organism can alter exposure and toxicity of contaminants and pathogens and seek to understand outcomes at different scales from individuals to populations and ecosystems.

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.