Contaminant Biology

Exposure Pathways

Filter Total Items: 72
Date published: June 1, 2021
Status: Active

Per-and Polyfluoroalkyl Substances (PFAS) Integrated Science Team

Per- and poly-fluoroalkyl substances (PFASs) are a large group of synthetic chemicals utilized for diverse applications including non-stick coatings, industrial lubricants, fire retardants in clothing and home goods, and as fire suppressors in firefighting foams. Due to the wide variety of PFAS uses and their resistance to breakdown, they have been detected in surface and groundwater resources...

Date published: May 26, 2021
Status: Active

Ecotoxicology and Ecological Risks of Per‐ and Polyfluoroalkyl Substances

Ecotoxicology and ecological risks of per- and polyfluoroalkyl substances are summarized to highlight critical gaps and uncertainties, and to provide potential approaches to fill those gaps, including the development of targeted monitoring programs and cross-disciplinary approaches.

Date published: May 26, 2021
Status: Active

Scientists Provide an Understanding of Anticoagulant Rodenticide Exposure in Non-Target Bird Species

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.

Date published: April 15, 2021
Status: Completed

Bioaccumulation of Mercury in Fish Varied by Species and Location in the Chesapeake Bay Watershed—Summary of Existing Data and a Roadmap for Integrated Monitoring

Fish mercury data from State monitoring programs and research studies within the Chesapeake Bay were compiled and summarized to provide a comprehensive overview of the variation in fish mercury concentrations among species and habitats within the watershed. These data are put into context with existing health benchmarks for humans, birds, and fish. Scientists also provide a roadmap for an...

Date published: April 7, 2021
Status: Completed

Flood Redistributes Mercury in Grand Canyon Aquatic Food Webs

Scientists coupled the concepts of energy flow through food webs with measurements of mercury in organic matter and animals to estimate mercury fluxes and fate during an experimental flood in the Colorado River. The flood redistributed mercury in simple, upstream food webs but not in more complex, downstream food webs. 

Date published: April 6, 2021
Status: Completed

Science to Understand Low-Level Exposures to Neonicotinoid Pesticides, their Metabolites, and Chlorinated Byproducts in Drinking Water

Scientists reported the discovery of three neonicotinoid pesticides in drinking water and their potential for transformation and removal during water treatment. The research provides new insights into the persistence of neonicotinoids and their potential for transformation during water treatment and distribution, while also identifying granulated activated carbon as a potentially effective...

Date published: March 16, 2021
Status: Completed

Clothianidin Exposure Associated with Changes in Tadpole Behavior

During a laboratory exposure study, tadpole movement decreased with increased concentrations of clothianidin, a neonicotinoid pesticide. Decreased movement could affect a tadpole’s ability to forage, escape predation, and metamorphose before ponds dry.

Date published: March 1, 2021
Status: Completed

Bird Hatchling Development Following Exposure to Environmentally Relevant Levels of Brominated Flame Retardants

Scientists performed laboratory studies with American kestrels and zebra finch to determine the effects of brominated flame retardant exposure on hatchlings. They found evidence that exposure while in the egg disrupted thyroid function in female American kestrel hatchlings and affected nestling body condition in zebra finch hatchlings, but no other effects were detected.


Date published: July 27, 2020
Status: Active

Dragonfly Larvae are Effective Bioindicators of Mercury Exposure in Fish and Amphibians—Results of Citizen Science in 100 National Parks and Protected Places

Mercury concentrations were measured in dragonfly larvae across more than 450 sites in 100 national parks and protected places as part of a partnership among Federal agencies, academic researchers, and more than 4,000 citizen scientists.  Mercury concentrations in dragonfly larvae were positively correlated with mercury concentrations in fish and amphibians living in the same...

Contacts: Collin Eagles-Smith, Colleen Flanagan Pritz
Date published: June 11, 2020
Status: Completed

U.S. Geological Survey Microbiologist Selected as an American Society for Microbiology Distinguished Lecturer

Dale Warren Griffin, a U.S. Geological Survey (USGS) environmental public-health microbiologist, was selected as a Waksman Foundation Distinguished Lecturer for the 2020–22 American Society for Microbiology (ASM) Lecture Series. 

Date published: June 4, 2020
Status: Completed

Framework for Examining Stream Ecosystem Health in Areas of Shale Gas Development—A Multi-Parameter Watershed-Based Case Study in Pennsylvania

In a case study of 25 headwater streams in Pennsylvania, no statistically significant associations were determined between shale gas development and geochemical tracers of produced waters or measures of microbial and macroinvertebrate community composition.  Although the results are specific to the region studied, the integrated biological and geochemical framework provides a tool for...

Date published: November 13, 2019
Status: Completed

Food Web Changes Dampen Expected Reductions in Lake Trout Mercury Levels in Lake Michigan—Invasive Species Play Major Role

Combined analyses of mercury, nitrogen, and carbon isotopes in archived lake trout (Salvelinus namaycush) tissues and sediment cores in Lake Michigan from 1978 to 2012 indicated that lake trout mercury concentrations mirrored declines in mercury sources prior to the arrival of invasive species that changed mercury transfer through the food and dampened the expected decreases in mercury...