Skip Links

USGS - science for a changing world

Open-File Report 2015–1113

Chemical Mixtures and Environmental Effects: A Pilot Study to Assess Ecological Exposure and Effects in Streams

By Herbert T. Buxton, Timothy J. Reilly, Kathryn M. Kuivila, Dana W. Kolpin, Paul M. Bradley, Daniel L. Villeneuve, and Marc A. Mills

Thumbnail of and link to report PDF (880 KB)Summary

Assessment and management of the risks of exposure to complex chemical mixtures in streams are priorities for human and environmental health organizations around the world. The current lack of information on the composition and variability of environmental mixtures and a limited understanding of their combined effects are fundamental obstacles to timely identification and prevention of adverse human and ecological effects of exposure. This report describes the design of a field-based study of the composition and biological activity of chemical mixtures in U.S. stream waters affected by a wide range of human activities and contaminant sources. The study is a collaborative effort by the U.S. Geological Survey and the U.S. Environmental Protection Agency. Scientists sampled 38 streams spanning 24 States and Puerto Rico. Thirty-four of the sites were located in watersheds impacted by multiple contaminant sources, including industrial and municipal wastewater discharges, crop and animal agricultural runoff, urban runoff, and other point and nonpoint contaminant sources. The remaining four sites were minimally development reference watersheds. All samples underwent comprehensive chemical and biological characterization, including sensitive and specific direct analysis for over 700 dissolved organic and inorganic chemicals and field parameters, identification of unknown contaminants (environmental diagnostics), and a variety of bioassays to evaluate biological activity and toxicity.

First posted June 30, 2015

For additional information, contact:
Program Coordinator
Toxic Substances Hydrology Program
Environmental Health Mission Area
U.S. Geological Survey
12201 Sunrise Valley Dr, MS 314
Reston, VA 20192
Environmental Health
Toxics Program

Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge. More information about viewing, downloading, and printing report files can be found here.

Suggested citation:

Buxton, H.T., Reilly, T.J., Kuivila, K.M., Kolpin, D.W., Bradley, P.M., Villeneuve, D.L., and Mills, M.A., 2015, Chemical mixtures and environmental effects—A pilot study to assess ecological exposure and effects in streams: U.S. Geological Survey Open-File Report 2015–1113, 12 p.,

ISSN 2331-1258 (online)


Contaminant Mixtures in Surface Waters

The Challenge of Chemical Mixtures

Environmental Health Effects of Chemical Mixtures

A Pilot Study

Pilot Study Approach

Pilot Study Significance

Integrated Approach to Chemical Mixtures Assessment, Source Identification, and Mitigation

Federal Role


References Cited

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Wednesday, December 07, 2016, 09:43:00 PM