By Lulu Fregoso & Paul Mathewson, Ph.D.
Summary
Contaminated sediment is a persistent environmental concern in Wisconsin’s inland lakes, rivers, and the Great Lakes. Contaminants such as PCBs, PFAS, PAHs, and heavy metals like mercury can bind to sediment that settles at the bottom of waterbodies. Once present in sediment, these contaminants can enter aquatic food webs and build up in the tissue of fish, exposing people who eat those fish to the contaminants. Exposure to fish contaminants has been linked to a range of health impacts including harms to the brain and nervous system, organ damage, low birthweight, and certain cancers. Fish contamination also raises important environmental justice concerns. Subsistence anglers, tribal nations, and certain immigrant communities, including Hmong and Burmese populations, often consume larger quantities of locally caught fish and may face higher exposure risks.
Key takeaways:
- Contaminated sediment is a persistent source of pollution in Wisconsin waterbodies and an important contributor to fish contamination.
- Statewide, 26 lakes, impoundments, and reservoirs—totaling nearly 60,000 acres—and 78 stretches of rivers and streams—totaling 930 miles—are impaired due to contaminated sediment.
- Fish consumption represents an important health concern in Wisconsin, where fishing is culturally, recreationally, and economically important.
- Mercury, PCBs, and PFAS are the most significant contaminants affecting fish consumption safety in Wisconsin.
- 44 lakes or stretches of rivers have advisories related to PCBs, 28 have advisories related to PFOS, and 106 have advisories related to mercury.
- Pregnant women, children, subsistence anglers, and certain marginalized communities face disproportionately higher exposure risks.
