Passive sampling method for measuring sediment contaminants validated in laboratory

SCCWRP and its partners have completed the validation phase of a two-year study that aims to adapt commercially available passive sampling devices to measure the freely dissolved concentration of CECs in sediment.

The validation phase provides a laboratory proof-of-concept that polyethylene film – a cheap and widely available plastic material – can accurately detect contamination in sediment samples that are just a few ounces in size over an accelerated 10-day testing period.

The passive sampling devices are now being tested on sediment samples collected from dozens of sites across San Diego Bay that reflect a range of bulk sediment contamination levels. SCCWRP and its partners also are testing the utility of other plastic materials for measuring high-priority CECs, including the pesticide fipronil that can be toxic to aquatic life at low levels.

Passive sampling devices have the potential to provide a more accurate measurement of the “bioavailable” portion of chemical contaminants that could be ingested and absorbed by sediment-dwelling organisms – a contrast to conventional measurement methods such as bulk sediment chemistry.