Ecotoxicological evaluation of TCPP (phosphorus flame retardant) by using D. magna toxicity tests

In this project, it is aimed to carry out ecotoxicological risk assessment of a phosphorous flame retardant substance named as Tris (1-chloro-2-propyl) phosphate (TCPP) both with Daphnia magna toxicity tests and by determining total protein content and enzyme (AChE and GST) activities used as biomarker in biochemical toxicity. Acute toxicity tests have been performed in accordance with the standard Daphnia sp. immobilization test protocol (OECD, 2004; Test Guideline 202), by using static system. Chronic toxicity tests have also been performed in accordance with the standard D. magna reproduction test protocol (OECD, 2012; Test Guideline 211), by using semi-static renewal system. AChE and GST enzyme activities, and total protein content have been determined according to Ellman's method (1961), Habig (1974) and Bradford (1976), respectively. 48 h EC50 value of TCPP on D. magna were 23,031 µl/l. At the end of the acute toxicity test, the total protein content per Daphnia magna was statistically significantly higher than control group. In the highest concentration group, a statistically significant decrease in AChE activity and a statistically significant increase in GST activity were observed. As a result of the chronic toxicity test, a statistically significant increase in the mean number of offspring per parent in the two highest concentration groups (0.3 and 0.9 μl/l) was determined. When the average number of offspring per parent was taken into account, the NOEC and LOEC values were found to be 0.1 and 0.3 μL / l, respectively. Generally, there were a statistically significant increases in height lengths of the individuals in the application group according to the control group. There was no statistically significant difference between the test and control groups in the total protein content and AChE activity in chronic toxicity tests. Although there was a slight increase in GST activity compared to the control group, this increase in activity was statistically significant only at concentrations of 0.01, 0.1 and 0.3 μl / l.