Sex hormone disruption induced by biodegradable plastic extracts compared with conventional plastics in H295R cells and adult male zebrafish.

Biodegradable plastics are increasingly replacing conventional plastics derived frompetroleum-based plastics; however, their potential endocrine-related hazards remain insufficiently characterized. In this study, we selected six biodegradable food contact articles composed of polybutylene adipate terephthalate (PBAT), polylactic acid (PLA), or PBAT + PLA blends, along with two conventional high-density polyethylene (HDPE)-based articles, and evaluated the endocrine disrupting effects of their acetone extracts using both in vitro (H295R, human adrenocortical cells) and in vivo (adult male zebrafish) assays. Exposure to these extracts significantly altered sex hormone profiles in zebrafish, characterized by increased estradiol and decreased testosterone or 11-ketotestosterone. These changes were accompanied by the upregulation of key steroidogenic genes, including CYP19A1 in H295R cells and cyp19a1 in zebrafish. Notably, several biodegradable plastic extracts induced endocrine disrupting responses comparable to, or exceeding, those induced by conventional HDPE. Given the similarity of hormonal responses across different polymer-based plastics, the observed endocrine disruptions are more likely to be related to intentionally added substances and non-intentionally added substances (NIAS), rather than to the base polymers themselves. Overall, our findings challenge the assumption that biodegradable plastics are necessarily safer than conventional non-biodegradable plastics and emphasize the need for comprehensive toxicological evaluation of biodegradable consumer products, particularly those intended for food contact or direct dermal or oral exposure.