Two-generational effects of Benzophenone-3 on the aquatic midge Chironomus riparius

Organic UV-filters are emergent contaminants continuously released into the aquatic ecosystems. These compounds are persistent showing potential for bioaccumulation. Partial life-cycle tests may underestimate the toxicity of UV-filters especially since these compounds have shown to act as endocrine disruptors. In the present study, the benthic aquatic insect Chironomus riparius was exposed to a gradient of Benzophenone-3 (BP3) concentrations over two generations to assess effects over a full life cycle from the first-instar larvae in the parental (P) generation (emergence, fecundity and fertility) until emergence in the subsequent generation (filial - F1). Recovery from exposure was also assessed after one generational exposure. Our results showed that concentrations of up to 8mg BP3/kg, elicited no effects regarding emergence rate and development time of C. riparius in the P generation. Our results also showed that C. riparius fecundity was not affected by BP3 exposure, but a strong dose-response relationship was observed for fertility with none of the egg ropes hatching at 8mg BP3/kg. Regarding effects observed in the F1 generation, emergence and development time were impaired by continuous exposure to BP3. Moreover, reduced emergence and changes in development time were observed in the F1 generation maintained in control/clean conditions but whose parents were exposed to BP3. Results found in this two-generational study clearly show reproductive effects of BP3 on C. riparius that would not be detected using standard tests. Full life cycle and multigenerational assays are critical to properly evaluate the population level effects of endocrine disrupting compounds such as organic UV-filters.