Contaminants in lake sediment cores
Our Persistent, Bioaccumulative, and Toxics (PBT) Monitoring program conducts ongoing studies to evaluate toxic chemical trends in lake sediment. We study PBT chemicals such as flame retardants and per- and polyfluoroalkyl substances on a rotating schedule. This information is used by policy makers to support 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 the deepest part of each lake 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.
Our latest methods are in the publication Quality Assurance Project Plan: Monitoring Persistent, Bioaccumulative, and Toxic Chemicals (PBTs) Using Age-Dated Lake Sediment Cores: 2023–2027.
Our latest publication, PBT Chemical Trends Determined from Age-Dated Lake Sediment Cores, 2017 Results, describes the 2017 sampling year, because it takes some years to analyze the chemicals. This and other reports are on the Freshwater Sediment Monitoring publications page.