Exposure Pathways

Exposure and toxicity of environmental mercury to birds can be enhanced or lessened due to the available sources and forms of mercury and other species dependent factors such as life stage, migratory patterns, foraging and nesting behaviors, transfer of mercury from mothers to eggs, and sex. For example, mercury exposure can lead to sublethal toxicological effects that can influence parental...

Chloride and metals in oil and gas co-produced wastewaters (often referred to as brines) are commonly perceived as contaminant hazards for biota. Amphibian abundance in the Prairie Pothole Region affected by historic oil and gas co-produced wastewaters was lower in wetlands with high concentrations of chloride indicating an actual contaminant hazard. Metals detected in sediments and amphibian...

Perfluoroalkyl substance (PFAS) concentrations in tree swallows ( Tachycineta bicolor) breeding at Clarks Marsh near a decommissioned U.S. Air Force base in Michigan were among the highest concentrations ever documented in birds indicating significant PFAS exposures. In contrast to previous studies where reproductive impairment was documented at lower PFAS exposure, there were no adverse effects...

Scientists determined what happens to the neonicotinoid insecticide, imidacloprid, on coated wheat seeds once ingested by Japanese quail (Coturnix japonica)—a model species for free-range, seed-eating, upland game birds. Imidacloprid was found to be rapidly adsorbed, metabolized, and excreted, and resulted in no overt signs of toxicity during a controlled laboratory study.

Science from the U.S. Geological Survey (USGS) and other entities has shown that a mixture of natural and synthetic estrogens and other similar chemicals are discharged from wastewater treatment plants (WWTPs) to streams and rivers.

Adult frog exposure to pesticides in aquatic and terrestrial habitats was quantified using a novel combination of radio telemetry and passive sampling techniques to better understand factors affecting frog health and survival in agricultural landscapes.

The Bioactive Chemicals Research Laboratory applies a collaborative transdisciplinary approach to conduct research to minimize the risk to human and aquatic organism health from exposure to contaminants in water supplies.

Microbiologists at the Michigan Bacteriological Research Laboratory (MI-BaRL) use a wide array of traditional and modern molecular approaches to evaluate microbial pathogens and antimicrobial resistance pathways in the environment.

Scientists explored the suitability of the DeFacto Reuse in our Nation's Consumable Supply (DRINCS) model to estimate the likelihood of contaminants from upstream wastewater discharges to enter drinking water facility intakes.

Four papers by U.S. Geological Survey (USGS) scientists document tree swallow ( Tachycineta bicolor) chemical exposure, physiological responses, and reproductive success in the Great Lakes region. These studies were designed to understand if there are health threats to swallows from contaminant exposure, and to provide resource managers with information about the actual as opposed to the perceived...

The Fishing, Hunting, and Subsistence Living Integrated Science Team focuses on contaminant and pathogen exposures in the environment that could impact the presence and vitality of fish and wildlife populations that drive commercial, recreational and subsistence activities such as hunting and fishing. If actual risks are identified this project will inform how to economically and effectively...

In a study designed to help resource managers when considering mercury exposure risk, scientists determined that sulfur cycling—a process closely related to mercury methylation rates—and ecological conditions that influence exposure are important factors affecting fish mercury concentrations in estuarine wetlands.