Analysis of Arsenite Acute Toxic Effects Based on Bayesian Model Averaging in Embryo, Larva, Juvenile and Adult Zebrafish

Arsenic is a ubiquitous environmental pollutant with well-documented human health risks, among which trivalent arsenic (arsenite) exhibits the highest toxicity. Although the acute toxicity of arsenite has been extensively studied in zebrafish embryos, its effects across other developmental stages remain largely unknown. In the present study, the acute toxicity of arsenite was evaluated across four zebrafish life stages—embryo, larva, juvenile, and adult—using both probit regression and Bayesian Model Averaging (BMA). Both methods revealed that LC50 values progressively decreased with increasing exposure time across all life stages, and susceptibility followed the order of embryo < larva < juvenile < adult. Additionally, Benchmark Dose (BMD), Benchmark Dose Lower Bound (BMDL), and Benchmark Dose Upper Bound (BMDU) values decreased with prolonged exposure, confirming a clear dose–response relationship. Notably, LC50 values estimated by BMA were consistently higher than those derived from probit regression, suggesting that the conventional approach may produce conservative estimates. Our findings not only establish a robust foundation for arsenic risk assessment across the entire zebrafish life cycle, but also provide experimental evidence that calls for a life-stage-informed revision of current arsenic safety thresholds.