Our Persistent, Bioaccumulative, and Toxics (PBT) Monitoring program conducts ongoing studies to evaluate toxic chemical trends in lake sediment. We study lead and mercury annually, as well as some other chemicals such as flame retardants and perfluoroalkyl substances, often called PFOS, periodically. This information is used by policy makers to support the development of chemical action plans and agency toxics reduction strategies.
We have collected sediment cores at three lakes every year since 2006. We collect a single sediment core from beneath each lake bed to construct historical deposition profiles of chemicals in the environment. We choose new lakes each year to achieve a broad spatial coverage of the state and to target waterbodies based on the parameters to be analyzed. Selected lakes cover a range of potential contaminant sources.