Factors influencing organochlorine pesticides distribution in the Brisbane River Estuarine sediment, Australia.

Sediment samples collected from Brisbane River were analysed for organochlorine pesticide residues (OCPs). The factors influencing OCPs distribution in the sediment were investigated using multivariate analytical tools. Thirteen OCPs were detected in the sediment with concentrations ranging between below detection to 83.9ng/g, and detection frequency >90%. With the exception of dieldrin, the OCP inputs appear to be historical and may cause adverse ecological impacts. Multi-criteria ranking of the factors influencing the OCPs (except dieldrin) distribution in the sediment revealed that TOC>silt>intensive urban land use>population>seasons. Dieldrin distribution is significantly influenced by season>TOC>silt>intensive urban land use>population. The study helps to prioritise factors required for managing OCPs contamination in sediments and identification of appropriate mitigation measures.