Acute and Chronic Toxicity of Propylparaben in the Freshwater Snail Biomphalaria glabrata: Effects on Survival, Growth, Reproduction, and Histopathology

Propylparaben (PP) is a widely used preservative in cosmetics, pharmaceuticals, and food products, and its potential toxicity to non-target aquatic invertebrates remains a concern. This study used the freshwater snail Biomphalaria glabrata as a model organism to evaluate the toxic effects of PP through acute and chronic exposures at embryonic, newly hatched, and adult stages. Acute exposure experiments showed concentration-dependent mortality and developmental inhibition, with LC50 values of 36.69 mg/L (embryos, 168 h), 33.48 mg/L (newly hatched snails, 96 h), and 57.05 mg/L (adults, 72 h). Chronic exposure of adult snails to 10–49 mg/L PP for 21 days significantly reduced growth and reproductive output, and no embryo masses were observed at concentrations ≥ 25 mg/L. Histological observations revealed progressive damage to the hepatopancreas and gonads. These results demonstrate that PP induces multiple toxic effects in B. glabrata, affecting survival, growth, reproduction, and tissue structure under both acute and chronic exposure conditions. The findings provide experimental evidence for evaluating the ecological risks of paraben contamination in freshwater ecosystems.