Source-specific health risks and potential source-oriented biological effects of synthetic phenolic antioxidants in Mactra veneriformis from typical bays of the Bohai Sea and the Yellow Sea, China.

Synthetic phenolic antioxidants (SPAs) are emerging additive-derived contaminants widely detected in marine ecosystems, yet their source-specific health risks and potential source-oriented biological effects remain unclear. This study quantified 10 SPAs in Mactra veneriformis collected from the Bohai Sea and the Yellow Sea in May and August 2025 and integrated bioaccumulation, multi-pathway biomarker responses, and receptor modeling to establish a source-specific risk assessment framework. Total SPA concentrations ranged from 5802.21 to 14396.50 ng/g d.w. in May and increased to 13129.13 to 23676.85 ng/g d.w. in August. Biomarker analyses partly reflected coordinated activation of detoxification and antioxidant systems, accompanied by oxidative damage, neurotoxicity, and immunomodulation. Although most individual hazard quotients were below 1, assessment results support prioritizing AO1010 as a potential risk compound. Positive matrix factorization tentatively interpreted four sources: plastics (F1), rubber (F2), personal care products (F3), and petroleum/lubricants (F4). By coupling partial least squares regression with PMF, source-specific health risks (PMF-HQ) and potential source-oriented biological effects (PMF-IBR) were quantified alongside. By integrating the results of PMF-IBR and PMF-HQ, we ranked risk contributions as F2 > F1 ≈ F4 > F3, indicating that rubber-related inputs exert disproportionately high toxicological pressure. This study establishes a source-specific risk control priority framework for emerging contaminants in coastal ecosystems.