Effect of Microplastic Types on the In Vivo Bioavailability of Polychlorinated Biphenyls

Thisstudy investigated the effect of MP type on the bioavailabilityof HOCs, providing insights into exposure from co-occurring HOCs andMPs. As MPs are released into the soil, various equilibriumstatusesare expected. MPs could play roles as a "source," a"cleaner," or a "sink" of HOCs. Threetypes of MPs (LDPE, PLA, and PS) were selected to study their effecton polychlorinated biphenyl (PCBs) relative bioavailability (RBA)measured by a mouse model. As a "source" of HOCs, exposureto MP-sorbed PCBs resulted in their accumulation in adipose tissuewith PCB RBA as 101 & PLUSMN; 6.73% for LDPE, 76.2 & PLUSMN; 19.2% for PLA,and 9.22 & PLUSMN; 2.02% for PS. The addition of 10% MPs in PCB-contaminatedsoil led to a significant (p < 0.05) reductionin PCB RBA (52.2 & PLUSMN; 16.7%, 49.3 & PLUSMN; 4.85%, and 47.1 & PLUSMN;5.99% for LDPE, PLA, and PS) compared to control (75.0 & PLUSMN; 4.26%),implying MPs acted as "cleaner" by adsorbing PCBs fromthe digestive system and reducing PCB accumulation. MPs acted as a"sink" for PCBs in contaminated soil after aging, butthe sink effect varied among MP types with more pronounced effectfor LDPE than PLA and PS. Therefore, the role played by MPs in bioavailabilityof HOCs closely depended on the MP types as well as the equilibriumstatus among MPs, soil, and HOCs.