Exposure Pathways

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.

The U.S. Geological Survey (USGS), in collaboration with the U.S. Fish and Wildlife Service (USFWS) and other disease specialists, have published reports during the past 12 years with information about the geographic distribution of diseases, specific pathogens, disease ecology, and strategies to avoid human exposure and infection for seven zoonotic diseases.

Seventeen naturally occurring trace elements, including those associated with adverse health impacts when birds are exposed to toxic levels (iron, lead, mercury, selenium, zinc, cadmium, and arsenic) were measured in small birds without harm. The nonlethal method was developed for hummingbirds, with Anna's hummingbirds ( Calypte anna ) as a test species and can be more broadly applied to other...

Scientists found that naturally occurring arsenic in aquifer sediments was mobilized into groundwater and attenuated through reattachment to sediments within an underground petroleum plume. Understanding these patterns identifies anthropogenic factors that affect arsenic presence and magnitude in groundwater.

Neonicotinoids were not detected in native prairie plants placed next to agricultural fields several years after discontinuation of neonicotinoid seed treatment. In addition, neonicotinoid concentrations were lower or absent in soils and runoff at sites with the native prairie strips.

Scientists optimized existing methods to collect and identify microorganisms including Bacillus anthracis, a pathogenic microorganism, in 4,800 soil samples across the United States, and developed a geographic information system (GIS)-based application to visualize microorganism occurrence throughout the United States.

This pilot study provided baseline data on avian influenza virus (AIV) occurrence in groundwater underlying poultry farms and documented the challenges for conducting a pathogen transport study during a disease outbreak.

A National Park Service (NPS) and U.S. Geological Survey (USGS) study determined the concentrations, potential for degradation, and potential for aquatic and terrestrial animal exposure to organic contaminants in water and sediment within the flood-plain/aquatic environments of Congaree National Park which is located downstream from urban and agricultural areas.

This study provides a method for quantifying changes in the spatial extent of cyanobacterial blooms at local and regional scales using remotely sensed data to determine if bloom occurrence and size are increasing or decreasing for inland water resources.

This laboratory-based study provides information for understanding enhancement of trichloroethene (TCE) biodegradation in a simulated groundwater system.

Commonly used chemicals (including fragrances, detergents, fire retardants, plasticizers, and antibacterials) transferred to wastewater treatment plants were detected in municipal wastewater biosolids applied to agricultural field plots and subsequently detected in the runoff transported from the plots during precipitation events.

This study provides new information about the composition and concentrations of 5 parabens—preservatives in pharmaceuticals and personal care products—present in biosolids collected from 14 municipal wastewater treatment plants across the United States.