Effects of exposure to pharmaceuticals (diclofenac and carbamazepine) spiked sediments in the midge, Chironomus riparius (Diptera, Chironomidae).

Human and veterinary pharmaceuticals and degradation products are continuously introduced into the environment. To date, there is a lack of information about the effects of pharmaceuticals in spiked toxicity tests with non-target organisms. In this study, we have evaluated the effects of exposure to two common pharmaceuticals in the midge Chironomus riparius in spiked sediment experiments. The selected pharmaceuticals are the nonsteroidal anti-inflammatory drug (NSAID): diclofenac (DF) and the anti-depressant drug carbamazepine (CBZ). In order to assess the effects of the pharmaceuticals, a chronic toxicity test with the midge was carried out. The endpoints survival, growth and developmental stage by means of biomass, were measured after 10days, and emergence rates and sex-ratio (male/female) were measured after 21days of exposure. Significant mortality was observed in organisms at day 10 with a 40% of larvae surviving in the highest exposure concentration of CBZ. DF decreased the emergence ratio with respect to the controls in organisms exposed at concentrations of 34.0μg·g whereas CBZ reduced the growth of the midges (30,6% with respect to the control) and induced a significant change in sex-ratio at concentrations of 31.4μg·g. The results obtained in the present study indicate possible adverse effects on aquatic invertebrates, which should be taken into account for environmental risk assessment of pharmaceutical compounds in sediments.