USGS Study Detects Algal Toxins in Southeastern U.S. Streams

The U.S. Geological Survey (USGS) has published the findings from a study that detected microcystins (algal toxins) in 39 percent of the small streams assessed throughout the southeastern United States.  The study looked at 75 streams in portions of Alabama, Georgia, North Carolina, South Carolina, and Virginia.  Although the maximum microcystin concentration measured in this study (3.2 µg/L) did not exceed World Health Organization moderate risk thresholds (10 µg/L), further research is needed to understand the potential effects on water quality and related environmental health concerns in downstream aquatic ecosystems, lakes, and drinking water reservoirs.

This is the first of several regional assessments of algal toxins, which will provide context for the design of future environmental health studies.  These studies will investigate land-use and other factors that may influence or create new environmental pathways of exposures to cyanobacteria and associated toxins.  Ongoing work by the USGS in the Pacific Northwest and planned work in the northeastern United States and California will expand the understanding of cyanobacteria and toxins in a wider variety of aquatic ecosystems.

More information about this study can be found here. For questions, please contact Keith Loftin of USGS at or 785-832-3543.