Toxic Substances Hydrology Program


Toxic Substances Hydrology Program scientists develop and apply advanced analytical methods, field investigations, laboratory studies, and modeling capabilities to understand sources, movement, and exposure pathways of chemical and microbial contaminants in the environment. They are integrated with Contaminant Biology Program Scientists who then determine the toxicity and effects of contaminants.

Featured Science Activities

Featured Science Activities

Our Science Feature Articles highlight recent USGS environmental health science activities.

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GeoHEALTH-USGS Newsletter

GeoHEALTH-USGS Newsletter

The GeoHEALTH-USGS Newsletter provides information on new USGS science activities related to safeguarding the health of fish, wildlife, domesticated animals, livestock, and people from environmental exposures to contaminants and pathogens.

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Date published: March 20, 2019

What's New with Our Budget in Fiscal Year 2020

Information on funding for Environmental Health Mission Area programs for fiscal year 2020.

Date published: February 22, 2019

Fiscal Year 2018 USGS Environmental Health Mission Area Accomplishments

In Fiscal Year 2018 our two integrated programs – Contaminant Biology and Toxic Substances Hydrology Programs – provided essential information to understand the risks of environmental contaminants and pathogens.

"Everything we do is designed to safeguard the Nation's health, economy, and resources."

Date published: February 15, 2019

Environmental Health Mission Area Science Priorities for Fiscal Year 2019

The USGS Environmental Health Mission Area (EHMA)—through its integrated programs, the Toxic Substances Hydrology Program (TSHP) and the Contaminant Biology Program (CBP) — will continue its non-regulatory, non-advocacy science throughout 2019.


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Year Published: 2019

Geochemical factors controlling dissolved elemental mercury and methylmercury formation in Alaskan wetlands of varying trophic status

Transformations of aqueous inorganic divalent mercury (Hg(II)i) to volatile dissolved gaseous mercury (Hg(0)(aq)) and toxic methylmercury (MeHg) governs mercury bioavailability and fate in northern ecosystems. This study quantified concentrations of aqueous mercury species (Hg(II)i, Hg(0)(aq), MeHg) and relevant geochemical constituents in pore...

Poulin, Brett; Ryan, Joseph N.; Tate, Michael; Krabbenhoft, David; Hines, Mark E; Barkay, Tamar; Schaefer, Jeffra; Aiken, George R.

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Year Published: 2019

Tracking legacy mercury in the Hackensack River Estuary using mercury stable isotopes

Spatial redistribution of legacy mercury (Hg) contamination in the Hackensack River estuary (New Jersey, USA) was evaluated using mercury stable isotopes. Total Hg varied from 0.06 to 3.8 µg g-1 in sediment from the tidal Hackensack River and from 15 to 154 µg g-1 near historically contaminated sites in upper Berry's Creek, a tributary of the...

Reinfelder, John R; Janssen, Sarah E.

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Year Published: 2019

Use of high-throughput screening results to prioritize chemicals for potential adverse biological effects within a West Virginia Watershed

Organic chemicals from industrial, agricultural, and residential activities can enter surface waters through regulated and unregulated discharges, combined sewer overflows, stormwater runoff, accidental spills, and leaking septic-conveyance systems on a daily basis. The impact of point and nonpoint contaminant sources can result in adverse...

Rose, Levi D.; Akob, Denise; Tuberty, Shea; Colby, Jeff; Martin, Derek; Corsi, Steven; DeCicco, Laura