The Biotoxicity Of Chlorinated Flame Retardants Dechlorane Plus On Daphnia Magna

Dechlorane Plus (DP) is a high production volume(HPV),chlorinated flame retardant,which is used in a variety of commercial/industrial products.The results show that DP have the similar characteristics of persistent organic pollutants(PO-Ps),such as the refractory,long-distance transmission,biological enrichment nature. However,data on potential toxicological and molecular responses to exposure are lacking, especially for aquatic organisms.In this study,we use Daphnia magna as testing organisum,investigated the biotoxicity of DP via the acute,chronic toxicity and bioaccumulation.The main findings were as follows:1. In acute toxicity study,Daphnia magna was exposed to different doses of DP for48hours (up to100mg/L).No obvious dose-dependent effect was appeare-d.DP showed low toxicity to Daphnia magna, LD10=48.7mg/L.2. The results of Daphnia magna reproduction test showed that a long-term exposure of DP had a significant stimulating effect on the reproductive capacity of Daphnia magna,mainly on the number and size of broods per animal and a slight inhibitory effect on parental growth. Which implied that the main energy was used in the reproduction when Daphnia magna was suffering environmental stress.3. We studied the effects of DP on Daphnia magna by SOD,CAT enzymes activities and the contents of MDA,H2O2of Daphnia magna. The results showed that the activities of SOD and CAT had been induced and the contents of MDA had been little changed when Daphnia magna was exposed in DP solution in24h.The activities of SOD and CAT had been inhibited and the accumulation of MDA had been increased when Daphnia magna was exposed in DP solution in48h.It was implied that Daphnia magna was in a positive state of defense in24h, and the antioxidant system had the trend of damage in48h.But the changes were not significant.It was suggested that DP did not induce a significant oxidat-ive damage on Daphnia magna.4. The nutritional status of Daphnia magna prominently affected their bioac-cumulation potential of DP.Daphnia magna had a significant bioaccumulation p-otential of DP in starvation.