Species-specific biomagnification and habitat-dependent trophic transfer of halogenated organic pollutants in insect-dominated food webs from an e-waste recycling site

Aquatic, amphibious, and terrestrial organisms in or around a pond that was contaminated by e-waste were collected and persistent halogenated organic pollutants (HOPs) for these species were analyzed. Based on the stable isotope and dietary composition, the aquatic and terrestrial food webs and several insect-dominated food chains including insects - toads, insects - lizards, and insects - birds were constructed. Biomagnification factors (BMFs) for insect-dominated food chains and trophic magnification factors (TMFs) in aquatic and terrestrial food webs were calculated. The BMFs of HOPs (except DBDPE) in insect - bird food chains were significantly higher than those in insect - toad and insect - lizard food chains, indicating that HOPs accumulated more easily in homeotherms than in poikilotherms. Trophic magnification was present for most of the PCB congeners in both aquatic and terrestrial food webs. Differences between the trophic transfer of halogenated flame retardant in terrestrial and aquatic food webs were observed, with trophic magnification in the terrestrial food web but trophic dilution in the aquatic food web for most of chemicals (except for lower brominated PBDE congeners). Meanwhile, the contour plots of TMFs across combinations of log K-OW and log K-OA for terrestrial food web were distinct from those for aquatic food web. These results indicate that the biomagnification mechanisms of HOPs in aquatic food webs are different from those in terrestrial food webs, and further suggest that the bioaccumulation of contaminants in terrestrial ecosystems cannot be directly deduced from aquatic ecosystems.