MULTI-SPECIES TOXICITY OF HEAVY METALS AND ORGANIC POLLUTANTS AND THEIR OPPOSITE NEUROBEHAVIORAL EFFECTS

Ubiquitous chemical pollutants, including heavy metals, phthalates, bisphenols, pesticides, and polycyclic aromatic hydrocarbons (PAHs), are widely present in aquatic environments in China, posing potential risks to ecosystem health. To enable a comparative risk ranking of these diverse contaminants, this study selected eight representative substances: chromium (VI), lead (II), cadmium (II), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), deltamethrin (DM), and benzoapyrene (BaP). A multi-tiered toxicity evaluation was performed, including acute assays (luminescent bacteria Photobacterium phosphoreum and water flea Daphnia magna), a zebrafish embryo developmental toxicity test, and larval locomotor behavior analysis. The test organisms exhibited distinct sensitivity spectra: P. phosphoreum to \textPb^2+ , DM, BaP, and \textCd^2+ ; D. magna to DM and \textCd^2+ ; and zebrafish embryos to DM, DBP, \textCd^2+ , and BaP. All compounds showed time-dependent increases in toxicity ( \textEC_50 / \textLC_50 ). The rank order of developmental toxicity in embryos (DM > DBP > \textCd^2+ > BaP > BPA > \textCr^6+ > \textPb^2+ > DEHP) aligned with their 96h- \textLC_50 values. Critically, behavioral analysis uncovered a class-divergent neurobehavioral response: sublethal exposure to heavy metals ( \textCr^6+ , \textCd^2+ , \textPb^2+ ) elicited larval hyperactivity, in contrast to the hypoactivity induced by organic pollutants (DEHP, BPA, DM, BaP). Through its multi-species, multi-endpoint approach, this study not only pinpointed DM, C \textCd^2+ , and DBP as high-risk pollutants but also established a critical data foundation for ecological risk ranking and prioritization of typical contaminants in China’s aquatic environments. Moreover, the distinct, class-specific opposite behavioral phenotypes uncovered herein represent potential sensitive biomarkers for pollutant-type discrimination and early-warning monitoring.