Typical herbicide residues, trophic transfer, bioconcentration, and health risk of marine organisms

Atrazine, a potent herbicide for weeds removal during the growing season, has been widely used in China. It is known to be distributed in aquatic ecosystems with a long half-life, thus presenting a potential risk to species and consumers. This study analyzed the concentrations of degraded atrazine residues in marine organisms (N = 129) including 3 species of mollusks, 2 species of crustaceans, and 15 species of fish from a semi-enclosed bay, Jiaozhou Bay (JZB), adjacent to the Northwest Pacific Ocean in China. The corresponding trophic magnification factors (TMF), bioaccumulation factors (BCFs), and subsequent risks to final consumers were also determined. The results showed an average atrazine concentration of (0.301 ± 0.03) ng g^-1 and (0.305 ± 0.04) ng g^-1 in fish and invertebrates, respectively. The BCFs were (5.23 ± 1.75) L kg^-1 and (5.81 ± 1.31) L kg^-1 for fish and invertebrates, respectively. Atrazine was significantly bio-diluted in JZB through the sampled marine organisms with increasing trophic levels, with a TMF value below 1 (P < 0.01). An analysis of the species sensitivity distribution (SSD) predicted that<0.02% of species were exposed to a dissolved concentration of atrazine (57.88 ng L^-1) that would lead to detrimental effects, while risk quotients predicted low long-term risks for species in the bay. Finally, people with a diet limited to species from JZB were found to face no associated health risk due to a significantly small daily intake and target hazard quotient of atrazine. The corresponding non-carcinogenic effect showed no significant risk from seafood consumption.