Persistent Chemicals in Fish
- Challenge: Cardno ChemRisk® carried out a study to assess human exposures to dioxins, furans, and polychlorinated biphenyls (PCBs) as a result of consuming catfish in Southern Mississippi. Previous studies of organohalogen blood levels rarely accounted for the dietary characteristics of the local population, and were often attributed to industrial emissions.
- Approach: Farmed catfish were purchased from local markets and fish farms, while wild-caught catfish were fished directly from several Mississippi rivers. Fish were analyzed for dioxins, furans and PCBs. Estimates of daily dietary intake and potential for increased health risks were calculated.
- Findings: Cardno ChemRisk found that the amount of catfish consumed by some demographic groups can increase dioxin blood levels. Farm-raised catfish had lower levels of dioxin-like and non-dioxin-like compounds compared to wild-caught catfish. Increased risk of adverse health outcomes is not expected as a result of catfish consumption.
- Value: Cardno ChemRisk provided novel information regarding organohalogen levels in farm-raised and wild-caught catfish. Industries and environmental groups can more accurately characterize and attribute various sources of dioxins found in the blood. (Note: This study was funded entirely by Cardno ChemRisk and another consulting firm solely as a contribution to the scientific literature.)
- Selected Publications: Scott, L.L.F., D. F. Staskal, E.S. Williams, W.J. Luksemburg, J.D. Urban, L.M. Nguyen, L.C. Haws, L.S. Birnbaum, D.J. Paustenbach, and M.A. Harris. 2009. Levels of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in southern Mississippi catfish and estimation of potential health risks. Chemosphere. 74(7): 1002-1010.