Distribution Characteristics,bioaccumulation And Biomagnification Of Dechlorane Plus In The Polar Multimedia Environment

As a chlorinated flame retardant additive,Dechlorane Plus（DP）was widely used in electrical wirings,computer and television connectors,cable coatings,plastic roofing materials,and other polymeric systems.It was easy to release from the production,usage,recovery and final disposal of industrial products,causing environmental pollution.DP became ubiquitous in the environment.It was hazardous to human health and ecosystem because of bioaccumulation and biomagnification.Meanwhile,DP migrated to high latitudes and even polar regions with the global distillation effect.The ecosystem of polar areas was relatively isolated from most other regions,reveal the polar environmental occurrence,migration and bioaccumulation of DP,which were of great significance to better understand the pollution and risks under the global environment.The main research contents and results are as follows:To assess the distribution and migration law of DP in the North Pacific and the Arctic Ocean,DP in atmosphere and surface seawater was detected during the Chinese Arctic cruise.The results showed that DP was detected in all atmospheric and part of seawater samples.The concentrations of DP ranged from 0.40 to 15.99 pg/m³ and nd to 0.22 pg/L in air and seawater,respectively.The concentration of DP was higher in the coast of the Asia than that in the Arctic Ocean.The fractional abundance of the anti-DP(f_aint)was ranged from 0.01⁰.49 and decreased with increasing northern latitude,which indicated that a stereoselective depletion of the anti-DP during long-range atmospheric transport（LRAT）.The f_anti of seawater samples had no significant correlation with that of atmospheric samples（p>0.05）,which indicated that the distribution of DP isomers in seawater were influenced by micro-degradation、adsorption of sediments and so on.Comparing the composition and distribution of DP in the North Pacific and the Arctic Ocean,we found that LRAT and sea water transport were two main sources of DP in the Arctic.To provide the concentration level,distribution characteristics and the pollution sources of DP,the surficial soil and plant in Fildes Peninsula were analyzed in this study.The concentrations of∑DP in soil samples and plant samples were 57.86³36.24 pg/g dw and 27.41¹531.35 ng/g dw and 175.00³048.91 pg/g dw,respectively.The regional feature of DP in soil samples and plant samples was illustrated that human and animal activities were the important factors affecting the distribution of DP in Antarctic.The mean f_anti values estimated in the current soils（0.37±0.14）and plants（0.24±0.08）were similar to that in the atmosphere,which indicated that the LRAT was the main source of DP in Antarctic.The f_anti values were negatively correlated to DP concentrations in soil,suggesting that DP levels play an important role in determining the isomeric composition in soil.However,the plant was more susceptible to the atmosphere.Nine representative species were sampled and analyzed from the Fildes Peninsula to assess the biomagnification potential of DP in the Antarctic food web.Results showed the DP concentrations ranged from 0.25 ng/g to 6.81 ng/g lipid weight in Antarctic biota and the concentrations of anti-DP and syn-DP showed significantly positive correlations with TLs（p<0.05,r_a=0.85;r_s=0.81,respectively）,suggesting that syn-DP and anti-DP underwent biomagnification and the biomagnification ability of anti-DP was higher than that of syn-DP.The f_anti of the organisms(f_anti=0.23⁰.53)was lower than that of commercial products(f_anti=0.68),demonstrating f_anti was changed during long-range atmospheric transport or stereoselection enrichment through the food web.Furthermore,based on food web magnification factors（FWMF）comparison between DP and polychlorinated biphenyls（PCBs）,the biomagnification potential of DP was found to be similar to that of highly chlorinated PCBs.