PT14 Toxicity of Mixtures
Exhibit Hall
8:00 AM - Tuesday
(PT233) Combined Effects of Chemicals Detected in Wastewater Effluents on Daphnia magna.
Kim, S1, Ra, J1, Kim, K1, 1 Gwangju Institute of Science and Technology(GIST, formerly K-JIST), Gwangju, Korea
ABSTRACT- Mixture toxicity using Daphnia magna in acute test was evaluated on the ten various organic chemicals detected in wastewater effluents around Gwangju area. The chemicals were selected as the contribution of toxicity on D. magna considering the concentration of chemicals and their toxicity based on the reference toxicity. In general, the estimation of the mixture toxicity has been performed through both effect summation expressed by toxic unit and independent action (or concentration addition) calculated by response curve. In this study, we investigated the feasibilities of toxicity prediction by plotting the results from the calculation using the prediction method and those observed from the real toxicity test using D. magna. The results showed that the prediction by independent action(IA) model calculating the effect in response curve has a higher value of regression coefficient (r2 = 0.88) to the observed results than that by simple effect summation and concentration addition(CA) model. We also found the overestimated prediction of toxicity by effect summation. In addition, the CA model was unpredictable to estimate the combined effects of mixture chemicals in the range of high concentration or high toxicity. As a consequence, IA model was more appropriate to predict the mixture toxicity of chemicals with different types of mechanism action (i.e., chemicals in WWTP effluents) than other prediction models such as CA and effect summation model.
Key words: wwtp effluents, mixture toxicity, daphina magna