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.

Get Articles

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.

Get Newsletter


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.


Publication Thumbnail
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.

Publication Thumbnail
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.

Publication Thumbnail
Year Published: 2019

Demonstrating the value of Earth observations—methods, practical applications, and solutions—group on Earth observations side event proceedings

Executive SummaryThe U.S. Geological Survey, the National Oceanic and Atmospheric Administration, the European Association for Remote Sensing Companies, and the European Space Agency in coordination with the GEOValue Community hosted a side event to the Group on Earth Observations Plenary on October 23–24, 2017, in Washington, D.C. The workshop,...

Pearlman, Francoise; Lawrence, Collin B.; Pindilli, Emily J.; Geppi, Denna; Shapiro, Carl D.; Grasso, Monica; Pearlman, Jay; Adkins, Jeffery; Sawyer, Geoff; Tassa, Alessandra
Pearlman, F., Lawrence, C.B., Pindilli, E.J., Geppi, D., Shapiro, C.D., Grasso, M., Pearlman, J., Adkins, J., Sawyer, G., and Tassa, A., 2019, Demonstrating the value of Earth observations—Methods, practical applications, and solutions—Group on Earth Observations side event proceedings: U.S. Geological Survey Open-File Report 2019–1033, 33 p.,