Bioaccumulation of halogenated organic pollutants (HOPs) in insects from the North China Plain

Insects represent the most diverse and abundant animal group on Earth and play a key role in transferring pollutants from primary producers to higher trophic levels. This study investigated the concentrations of polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs), dichlorodiphenyltrichloroethanes (DDTs), and hexachlorocyclohexanes (HCHs) in ten insect species collected from an agricultural region in the North China Plain. Total HCH concentrations in insects were significantly higher than those of other halogenated organic pollutants (HOPs), with ground beetles presenting the highest HCHs levels, suggesting that agricultural activities as the predominant contamination source. Species-specific congener profiles were observed for DDTs, while other HOPs were dominated by CB 28, CB 187, BDE 209, and β-HCH. Fossorial insects had the highest HOPs concentrations, followed by aquatic and terrestrial species. Additionally, omnivorous insects accumulated more HOPs than most phytophagous and carnivorous ones. These findings highlight the role of habitat and feeding strategy in shaping pollutant bioaccumulation patterns, providing valuable insights into contaminant cycling within agricultural ecosystems.