Targeted and non-targeted analyses reveal trophic biomagnification of rubber-derived chemicals in an estuarine food web near China's largest rubber production region

The emergence of rubber-derived chemicals (RDCs) has garnered significant environmental attention, particularly N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q) linked to acute mortality in salmonids. However, the trophic transfer of RDCs within marine ecosystems is notably sparse. Here, we investigated RDCs in the Nandu River estuary near China's largest rubber production region through an integrated targeted and non-targeted approach. Twelve targeted and 28 non-targeted RDCs were identified in biological samples. For targeted RDCs, total mean concentrations (ng/g, wet weight) showed a descending order of crab (702) > shellfish (531) > snail (491) > shrimp (392) > cuttlefish (342) > fish (190), while those for non-targeted RDCs followed the order of fish (3.91 ×103) > shellfish (3.08 ×103) > cuttlefish (2.96 ×103) > shrimp (2.78 ×103) > snail (1.61 ×103) > crab (1.36 ×103). Thirteen RDCs exhibited biomagnification potential with trophic magnification factors (TMFs) of 1.05–3.24, while nine compounds displayed biodilution trends (TMFs: 0.56–0.93). Organism-water partition coefficients, derived from multi-parameter linear free-energy relationships, more accurately elucidate biomagnification mechanisms of RDCs. Furthermore, 60 % of RDCs exhibited persistence, bioaccumulation and toxicity properties. This research underscores the importance of integrating targeted and non-targeted approaches of RDCs in biomonitoring, offering a more comprehensive view of cumulative chemical risks to humans and wildlife.