Pollution Characteristics And Exposure Risk Of Dechlorane Plus In Fish From Daling River Estuarine

Daling River, the largest river in the western of Liaoning Province, has been polluted for many years and may result in ecological damage. Dechlorane Plus (DP), a widely used chlorinated flame retardant in the world, has the typical characteristics of Persistent Organic Pollutants (POPs),i. e. persistance in the environment for a long time, bioaccumulation within biota and biomagnification through food webs. Therefore, the existance of DP may be a threat to human healthy. It is necessary to investigate the levels and distributions of DP in organisms and assess the potential exposure risk of it.Tissues of goby (Eucyclogobius newberryi) and barracuda (Chelon haematocheilus) were collected from Daling River in2010and2011, respectively. DP concentrations (total, syn-and anti-DP) were detected in liver, brain and muscle samples from barracuda, as well as muscle samples from goby. Results domonstrated the existance of DP in all the samples detected, with the mean concentrations of91.65ng/g1w in all three barracuda tissue samples and29.06ng/g lw in goby muscle samples. The highest concentrations of total DP appeared in brain samples of barracuda (208.73ng/g1w), while the lowest concentrations of total DP appeared in muscle samples of goby (8.7ng/g1w). The distributions of DP varied in different tissues. In barracuda, DP concentrations in brain (mean140.28ng/g1w) are higher than liver (mean116.24ng/g1w) and muscle (mean73.34ng/g1w). Interestingly, the concentration of DP in goby muscle samples were quite lower (29.06ng/g1w) than barracuda.In addition, differential accumulation of DP isomers in different tissues and fishes were analyized by the calculation of fsyn value. For all samples analyed, the mean of fsyn value was0.44(range0.29-0.56), which is higher than that of commercial mixture (0.41) in China. These results indicate that syn-DP may preferentially accumulated in fish, compared with anti-DP. Futher analysis of fsyn values in different tissues of barracuda domostrated syn-DV may preferentially accumulate in liver and muscle, while anti-DP may preferentially accumulate in brain, as the fsyn values of liver and muscle were higher than brain. Above results suggest syn-and anti-DP may have different metabolic pathways in different tissues. Moreover, the fsyn values of muscle in goby were higher than barracuda, suggesting the accumulation abilities of DP isomers in different fishes varied.Based on above data, we calculated the daily intake of human (barracuda6.7×10-7and goby2.5×10-7mg/g/d) and reference dose (RfD5mg/g/d), and estimated the risk assessment of DP. As none of the HI values for DP exceed the benchmark value in this study, we presumed that fish collected from Daling River are safe to human.