Environmental Toxicology
Environmental Toxicology
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Assessing Environmental Chemical Mixtures in United States Streams
The U.S. Geological Survey (USGS) and the U.S. Environmental Protection Agency (EPA) are collaborating on a field-based study of chemical mixture composition and environmental effects in stream waters affected by a wide range of human activities and contaminant sources.
Comprehensive Assessment of Mercury in Streams Explains Major Sources, Cycling, and Effects
A new USGS report, Mercury in the Nation's Streams—Levels, Trends, and Implications, presents a comprehensive assessment of mercury contamination in streams across the United States. It highlights the importance of environmental processes, monitoring, and control strategies for understanding and reducing stream mercury levels. This report summarizes selected stream studies conducted by the U.S...
Contaminant Transport Models Aid in Understanding Trends of Chlorinated Ethenes in Public Supply Wells
U.S. Geological Survey (USGS) scientists used a mass–balance solute–transport model to enhance an understanding of factors affecting chlorinated ethene (CE) concentrations in a public supply well. They found that long–term simulated and measured CEconcentrations were affected by dense nonaqueous phase liquid (DNAPL) volume, composition, and by the bioavailability of organic carbon that drives...
Chemicals Found in Treated Wastewater are Transported from Streams to Groundwater
U.S. Geological Survey (USGS) scientists studying a midwestern stream conclude that pharmaceuticals and other contaminants in treated wastewater effluent discharged to the stream are transported into adjacent shallow groundwater. Other mobile chemicals found in wastewater are expected to have similar fates.
Pharmaceuticals and Other Chemicals Common in Landfill Waste
Landfill leachate contains a variety of chemicals that reflect our daily activities, U.S. Geological Survey (USGS) scientists concluded as a result of a nationwide study. Landfills are a common disposal mechanism for our Nation's solid waste from residential, commercial, and industrial sources. The scientists found that pharmaceuticals, personal-care products, and other contaminants of emerging...
Pipeline Crude Oil Spill Still a Cleanup Challenge after 30 Years
Research at a 1979 crude oil spill from a ruptured pipeline has exposed and helped to overcome many challenges facing an effective, cost-efficient cleanup of crude oil, U.S. Geological Survey (USGS) scientists have found. The environmental release of crude oil occurred near Bemidji, Minnesota.
Neuroactive Pharmaceuticals in Minnesota Rivers
A team of scientists from the U.S. Geological Survey (USGS) and the University of Colorado measured seven neuroactive pharmaceutical compounds in treated wastewater and downstream receiving waters at 24 sites across Minnesota. The analysis of samples collected upstream and downstream of wastewater treatment plants indicated that wastewater treatment plants were the major source of these chemicals.
Toxins Produced by Molds Measured in U.S. Streams
A team of scientists from the U.S. Geological Survey (USGS) and the Agroscope Reckenholz-Tanikon Research Station, Switzerland, found that some mycotoxins are common in U. S. stream waters. Mycotoxins are toxic compounds produced by molds (fungi) that can cause disease and even death in humans and animals. Mycotoxins can grow on a wide variety of crops.
Complex Response to Decline in Atmospheric Deposition of Mercury
U.S. Geological Survey (USGS) scientists found that mercury concentrations in shallow waters and methylmercury (MeHg) concentrations in fish in four lakes in Voyageurs National Park, Minnesota, were not consistent with decreases in the wet atmospheric deposition of mercury recorded at nearby monitoring stations for over a decade. Methylmercury is a toxic form of mercury (Hg) that accumulates and...
Biosolids, Animal Manure, and Earthworms: Is There a Connection?
Animal manure and biosolids, the solid byproduct of wastewater treatment, often are applied to agricultural crops to provide nutrients for plant growth and to improve the quality of soil. Earthworms studied in agricultural fields where manure and biosolids were applied have been found to contain organic chemicals from household products and manure. Earthworms continuously ingest soils and may...
Common Weed Killer is Widespread in the Environment
U.S. Geological Survey (USGS) scientists report that glyphosate, known commercially by many trade names, and its degradation product AMPA (aminomethylphosphonic acid) are transported off-site from agricultural and urban sources and occur widely in the environment. This study is the largest and most comprehensive assessment of the environmental occurrence of glyphosate and AMPA in the United States...
Measuring POEA, a Surfactant Mixture in Herbicide Formulations
POEA (polyoxyethylene tallow amine) is a surfactant with known toxic effects on aquatic organisms. POEA was added to the original formulation of the herbicide glyphosate to aid in its application and effectiveness at controlling weeds. U.S. Geological Survey (USGS) scientists developing methods to measure POEA in the environment have shown that it’s a complex and variable mixture of related...