Exposure Pathways

The U.S. Geological Survey (USGS) 2016 Early Career Excellence in Leadership Award was given to Dr. Denise M. Akob and Dr. Karl B. Haase. Drs. Akob and Haase have demonstrated outstanding leadership through their scientific accomplishments and service to the USGS.

Human enteric and bovine-specific viruses were detected in eight Great Lakes tributaries. Presence and concentration of human viruses increased in watersheds with greater than 25 percent urban influence and more than 2,900 people per square kilometer. Similarly, bovine viruses increased in watersheds having greater than 40 percent agricultural land influence and cattle densities greater than 50...

The Chesapeake Bay is the largest estuary in the United States and provides critical resources to fish, wildlife and people. For more than a decade, recreational fish species have been plagued with skin lesions and intersex conditions (the presence of male and female sex characteristics in the same fish) that biologists attributed to exposures to endocrine disrupting chemicals (EDCs)...

A new study highlights the complexity of chemical mixtures in streams and advances the understanding of wildlife and human exposure to complex chemical mixtures.

Study examines the potential adverse effects of fungicides on leaf decomposition by microbes and aquatic invertebrates.

Shifts in the overall microbial community structure were present in stream sediments that contained chemicals associated with unconventional oil and gas wastewaters. This work is part of a long-term study designed to understand persistence of chemicals from oil and gas wastewaters in sediments and water and how those factors might be related to exposures and adverse health effects, if any, on...

The addition of nitrate in a low oxygen groundwater resulted in the immobilization of naturally occurring dissolved arsenic and the conversion of nitrate to innocuous nitrogen gas.

A new study measures the transport of chemicals associated with unconventional oil and gas (UOG) produced waters downstream from a pipeline leak in North Dakota. This work is part of a long-term study designed to understand chemical persistence in sediments and water and how those factors might be related to contaminant exposures and associated with adverse health effects, if any, on organisms.

The presence of indicator bacteria, hepatitis E virus (HEV), and numerous bacterial pathogen genes increased following precipitation-induced runoff events in streams draining adjacent land surfaces in Iowa where swine manure was recently applied.

Scientists refined an existing speciation model to identify key biogeochemical processes controlling dissolved uranium bioavailability to a freshwater snail. This information is important to advance current understanding and prediction of the ecological risk posed by uranium mining to freshwater ecosystems, including federally managed lands such as in the Grand Canyon area.

Saharan dust nutrients, particularly iron, deposited episodically in tropical marine waters stimulate marine microbial bloom growth and change microbial community structure.

For the first time, U.S. Geological Survey (USGS), Virginia Institute of Marine Science, and the University of Connecticut scientists have detected active anammox bacteria in groundwater.