Phthalates released from microplastics can't be ignored: Sources, fate, ecological risks, and human exposure risks

Phthalates are widely used as plasticizers in plastic production. Due to the absence of covalent bonds with plastic polymers, phthalates can continuously leach from the plastics into the environment. As the ocean is the largest sink for microplastics, large amounts of phthalates could be released into the marine environment along with microplastics. Besides their migration and transformation in the marine environment, phthalates could be accumulated in organisms and exhibit endocrine-disrupting effects. This review summarizes the leaching mechanisms and influencing factors of phthalates from microplastics, the migration and transformation of phthalates in different media, and the environmental degradation processes. The toxic effects of phthalates and their ecological risks to marine ecosystems are outlined. Furthermore, human exposure risks to phthalates based on the levels of phthalate metabolites in urine worldwide are evaluated. Future research on phthalatemicroplastics interactions, toxicity of mixed phthalates, and conjugated metabolites are highly warranted.