Levels And Spatial Distribution Of Dechloranes In Several Typical Regions

Dechloranes,a new kind of chlorinated flame retardants,include Mirex(also known as Dechlorane),Dechlorane 602(Dec 602),Dechlorane 603(Dec 603),Dechlorane 604(Dec 604)and Dechlorane Plus(DP or Dec 605).In 1960s,Mirex was banned in the USA because of its toxicity and was replaced by Dec 602,Dec 603,Dec 604 and DP by Oxychem Inc.They are widely used in the production of electronic products,plastic roofs and other products.Although these substances have been used for nearly 50 years,the information such as production,usage,levels and spatial distribution of Dec 602,Dec 603,Dec 604 is still limited.The pollution sources of flame retardants include the production,usage and electronic waste(e-waste)dismantling and recycling process.The objective of this study was to understand the levels and spatial distribution of Dechloranes and to determine possible sources of Dechloranes in three typical regions.The study will contribute to assessing the pollution status of Dechloranes in China.On the basis of reported articles,we had established the analytical methods of Dechloranes in soil,sediment,water and atmosphere samples.Recoveries of target compounds were between 69%-121%and the relative standard deviation(RSD)were all below 15%.The methods can apply to detecting Dechloranes in environmental samples.We studied the levels and spatial distribution of Dechloranes in different environment media around DP manufacturing plant and e-waste dismantling areas as well as sediment of Lake Taihu.The findings are as follows:The concentrations of Mirex,Dec 602 and DP in surface soil around DP manufacturing plant ranged between 0.046-37.5 ng/g dry weight(dw),ND-0.103 ng/g dw and 0.665-102 ng/g dw.The concentrations of Mirex,Dec 602 and DP in surface sediment around DP manufacturing plant ranged between ND-41.0 ng/g dw,ND-0.356 ng/g dw and 0.165-65.1 ng/g dw.The concentrations of Mirex and DP in water ranged between ND-1.05 ng/L and ND-4.91 ng/L.The concentrations of Mirex,Dec 602 and DP in atmosphere were 825 pg/m3,2.52 pg/m3 and 5.17×103 pg/m3.The concentrations of Mirex,Dec 602 and DP in activated sludge were 2.05×103 ng/g dw,41.0 ng/g dw and 1.23×104 ng/g dw.The concentrations of Mirex,Dec 602 and DP in sewage inflow were 1.99×103 ng/L,3.04 ng/L and 1.59×104 ng/L.The concentrations of Mirex,Dec 602 and DP in sewage outflow were 2.58×103 ng/L,5.95 ng/L and 2.29×104 ng/L.The concentrations of Mirex and DP in surface sediment of Lake Taihu ranged from ND to 1.29 ng/g dw and from 0.051 to 2.10 ng/g dw.The concentrations of DP in soil,sediment,water and atmosphere in e-waste dismantling areas ranged from 0.115 to 26.4 ng/g dw,0.185 to 7.03 ng/g dw,0.843 to 1.56 ng/L and 11.2 pg/m3.The spatial distribution of Dechloranes in different environment media around DP manufacturing plant showed that the DP manufacturing plant was an important source of Dechloranes and there was also the unknown sources.Mirex in sediment of Lake Taihu were mainly distributed in the southeast corner and may came from the agricultural pollution.DP were mainly located in the northeast corner of Lake Taihu and may came from the industrial and municipal pollution.The spatial distribution of DP in the areas of e-waste dismantling indicated that the e-waste dismantling and burning process was an important source of DP.