Human health risk assessment for the land application of biosolids contaminated with persistent organic pollutants.

A human health risk assessment for the land application of Australian biosolids contaminated with persistent organic pollutants (POPs) was completed. The compounds evaluated were dioxins, polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dieldrin and chlordane. Four categories of human exposure have been identified and evaluated: direct human exposure, plant accumulation, animal accumulation, and drinking water. Models that predict chemical movement from biosolids-amended soil have been utilised to estimate human exposure. This risk assessment indicates that the chemicals evaluated do not pose an unacceptable risk of human exposure when land applying Australian biosolids containing levels of contaminants typically reported.