An overlooked environmental risk of a widely used non-ionic surfactant: Environmental toxicological effects of polysorbate 20 across life stages of the freshwater snail Biomphalaria glabrata.

Polysorbate 20 (Tween 20) is a widely used non-ionic surfactant applied in food, pharmaceutical, and experimental research fields. However, information on its potential effects on freshwater organisms across different life stages remains limited. In this study, the freshwater gastropod Biomphalaria glabrata was used to assess the acute and chronic toxicity of Polysorbate 20 across three developmental stages: embryos, newly hatched snails, and adults. Results showed that Polysorbate 20 induced life-stage-dependent toxicity in B. glabrata. Embryos and newly hatched snails were more sensitive to acute exposure, with LC50 values of 43.57 mg/L at 216 h and 48.21 mg/L at 96 h, respectively, whereas adults showed a higher 96 h LC50 of 324.5 mg/L. Chronic exposure to sublethal concentrations impaired reproduction and growth, as reflected by reduced egg mass production, inhibited shell growth, and altered body weight change. Histological analyses further revealed alterations in the gonads and hepatopancreas, indicating adverse effects on reproductive and digestive tissues. Overall, these findings show that Polysorbate 20 can adversely affect development, reproduction, growth, and tissue organization in B. glabrata, suggesting that its ecological effects on freshwater organisms warrant further attention.