Enrichment of Persistent\nOrganic Pollutants in Microplastics\nfrom Coastal Waters

Despite the adsorption of microplastics (MPs), the precise\nquantification\nof their concentrating effect on persistent organic pollutants (POPs)\nremains uncertain. Therefore, in this study, POPs in MPs, POPs in\nsuspended particulate matter (SPM), and dissolved POPs in seawater\nwere distinguished to quantify the enrichment factor (EF) for characterizing\nthe concentrating effects of MPs and SPM on POPs. The results showed\nthat the logarithm of EF (log EF) for POPs in MPs was 5.94 to 7.14.\nFor POPs, the concentrating effect of MPs was 1 to 2 orders of magnitude\ngreater than that of SPM. Moreover, for PCDD/Fs, PBDD/Fs, and PBDEs,\nthe concentrating effect of MPs was roughly comparable to that of\norganic matter in SPM, while it was 1 to 2 orders of magnitude higher\nthan that of organic matter for dioxin-like PCBs and PBBs. The MPs\nwere prone to sorbing highly toxic POP congeners. When the logarithm\nof the <i>n</i>-octanol–water partition coefficient\n(log <i>K</i><sub>OW</sub>) of POP homologues ranged from\n5.5 to 8.25, the log EF for POP homologues in MPs approximately was\nbetween 5 and 7. The heterogeneous MPs from the field environment\naffected their capacity to sorb POPs, causing a nonsignificant correlation\nbetween the enrichment factor and log <i>K</i><sub>OW</sub>.