Toxic Substances Hydrology Program
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Featured Science Activities
Our science activities are summarized in a series of feature articles that highlight recent U.S. Geological Survey (USGS) environmental health science activities. They are short summaries of peer-reviewed journal articles and USGS reports co-authored by our specialized teams of scientists.
Older featured science activities are on our old Web site.
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Nitrate Addition Enhances Arsenic Immobilization in Groundwater
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.
Sublethal Effects of Contaminants in Aquatic Food Webs—Research Challenges and Considerations for Future Studies
U.S. Geological Survey (USGS) and academic scientists partnered to identify challenges and provide considerations for future scientific study designs to advance our understanding of the often subtle sublethal effects of contaminants on individuals, populations, communities, and entire aquatic food webs.
No Evidence of Toxicity to Birds Ingesting Neonicotinoid-Coated Wheat Seeds During Controlled Laboratory Study
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.
Uranium in Springs Sampled Near the Grand Canyon Likely from Natural Sources
Scientists measured nine naturally occurring elements including uranium at 37 spring sites in the Grand Canyon area to establish baseline conditions and to understand the sources of uranium to local springs. Scientists found relatively greater concentrations of uranium at 6 of the 37 springs. A comprehensive geochemical analysis coupled with an understanding of the flow patterns in the area...
Pilot Study Provides Information on Contaminant Exposure from Tap Water at Residential and Workplace Sites in the United States
The U.S. Geological Survey (USGS), in collaboration with National Institutes of Health, U.S. Environmental Protection Agency, and academia, completed a pilot study to provide information on contaminant exposure from tap water at 26 locations including public and private supplies. Public-supply tap water generally met enforceable standards for those compounds with standards. Samples consisted...
Variability in Composition of an Oil Spill after more than 30 Years of Natural Attenuation
More than thirty years after an oil spill, hydrocarbons measured in groundwater near Bemidji, Minnesota, have been depleted between 25 and 85 percent. However, some components have remained for many decades and some are expected to remain longer indicating that natural attenuation is an effective but slow process. Compounds that are sufficiently soluble and resistant to biodegradation provide...
Per- and Polyfluoroalkyl Substances (PFASs) detected in Source Waters and Treated Public Water Supplies
This study, which measured 17 per- and polyfuoroalkyl substances (PFASs) in source and treated public water supplies from 25 drinking water facilities as part of a broader study of contaminants in drinking water across the United States, reports that PFASs were detected in all source water and public water supply samples collected. One sample exceeded the current U.S. Environmental...
Novel Approach Improves Understanding of Virus Occurrence in Drinking Water
Waterborne viruses, one of the leading causes of gastrointestinal illnesses, were measured in United States drinking water sources and finished water. Scientists used a combination of measurement and statistical techniques to overcome limitations to quantifying these viruses, thus offering an enhanced method for virus monitoring.
Understanding Drivers of Cyanotoxin Production in the Lake Okeechobee Waterway
The U.S. Geological Survey (USGS) and other researchers combined field and laboratory approaches in two studies to understand the factors that drive cyanobacterial bloom development and associated cyanotoxin production in Lake Okeechobee, the St. Lucie River and Estuary, and the Indian River Lagoon in response to the large-scale Lake Okeechobee cyanobacteria bloom in 2016.
Unique Methods Used to Understand Frog Exposure to Pesticides in Agricultural Settings
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.
Exploring the Suitability of a Modeling Approach to Estimate Contaminant Occurrence in Drinking Water Sources
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.
Systematic Approach to Understanding Tree Swallow Health in the Great Lakes Region—Science to Inform Restoration
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...