LAUSR

Equilibrium sampling based on silicone polydimethylsiloxane (PDMS) has been used to determine the concentrations of freely dissolved hydrophobic organic compounds (HOCs) and assess the thermodynamic potentials for bioaccumulation of these compounds in the aquatic environment. This allows the use of PDMS-based sampling techniques in assisting conventional sampling and extraction methods for the determination of the concentrations of HOCs in aquaculture products. This study presented an ex-situ demonstration of how well PDMS can inform the tissue residues and dietary risks of legacy or current-use organic chemicals in the aquaculture species from the farm ponds in Eastern China. For legacy contaminants such as polybrominated diphenyl ethers (PBDEs, n=10), a good agreement between the predicted concentrations based on PDMS and the measured lipid-normalized concentrations was observed for 60% of the studied biota, including both pelagic and benthic species. For pesticides currently used, such as pyrethroid (PE, n=4) and organophosphate pesticides (OPPs, n=7), the measured tissue residues were consistently higher than those predicted by PDMS, possibly caused by the continuous input from surroundings. For the organochlorine pesticides (OCPs, n=5), the only detected chemical (β-HCH) was also underestimated. Adjusted by ingestion rates of aquaculture products and toxicology data, the target hazard quotients (THQs) of these chemicals predicted from PDMS were generally comparable to those derived from measured concentrations in tissue due to the predominance of PBDEs. Overall, PDMS-based equilibrium sampling offered an alternative approach for the prediction of the tissue residues and dietary risks of PBDEs. Moreover, it should be applied with caution for PEs, OPPs and OCPs. Improving the application of PDMS for these chemicals in farm ponds warrants future study. This article is protected by copyright. All rights reserved.