Polybrominated Diphenyl Ethers In Soils Of North China And Human Expodures Via Non-dietary Intake

As a new kind of brominated flame retardants, Polybrominated Diphenyl Ethers(PBDEs) is widely applied in multiple industries. However, it is concerned byenvironmental and medical fields because of its potential (confirmed) biologicaltoxicity. Previous researchs found PBDEs has been detected in environmental mediaand human tissues all over the world. It is worth noting that China has become theelectronic waste disposal sites of the entire world. The high concentrions of PBDEshas been found in the electronic waste dismantling sites of China, such as Guiyu inGuangdong Province and Taizhou in Zhejiang Province. In fact, there are manyelectronic waste dimantling areas in China, including the North China. And somesecluded electronical waste dismantling areas bring great difficulties for researchesand management about PBDEs. In addition, Shandong Province, located in NorthChina, is one of the most important production bases of flame retardants (includingPBDEs) in China. However, researches aiming at PBDEs in North China are still veryscarce at present.Soil samples were collected in the North China, and the non-point pollution andpoint pollution were combined in this research. The “point” soil samples werecollected from electronical waste dismantling areas in Tianjin and production bases ofPBDEs in Shandong Province. The “non-point” soil samples were collected fromNorth China based on a gridded design across North China (Beijing, Tianjin, HebeiProvince, Shanxi Province, Shandong Province).The researches of “point” showed that BDE209is found to be the predominantcongener in all samples of Tianjin. Tetra-BDEs and Penta-BDEs are the maincomponents of the lower PBDEs, accounted for11.98-54.40%(34.44%) and8.34-52.87%(29.81%), respectively. PBDEs in soils of electronic waste recyclingpark in Jinghai County might come from DE-71and Saytex102E productions, andPBDEs contamination in other regions might be affected by the mixed Penta-BDEs and Deca-BDEs products. BDE209also is the predominant congener in Shandong. Itis different from Tianjin that Di-BDEs and Tetra-BDEs are the main components ofthe lower PBDEs, accounted for6.75-58.07%(29.22%) and2.50-70.99%(21.15%),respectively. The PBDEs contaminations in PBDEs producing sites (Weifang, Yantai)mainly come from the producing Deca-BDE products, the using of PBDEsproductions and transporting from PBDEs producing sites have impact on otherregions in Shandong. The study proves that there might be Penta-BDEs productionindusty, which levels of lower brominated congeners are much higher.The “non-point” results showed that PBDE congeners were found with highdetection frequencies, ranging from84%to100%. PBDE concentrations ranged from0.08to8264.87ng/g with a mean of202.27ng/g；BDE209was the predominantcongener, with concentrations of0.08-8148.10ng/g (mean,188.54ng/g). Theconcentrions of PBDEs in soils of North China varied greatly. There was a cleardecreasing trend in the concentrations of both lower and higher brominated congenersfrom the east toward the west of the region. Generally, relatively low levels of PBDEswere observed in North China, with the exception of some regions, particularlyShandong Province and Tianjin. The concentrations of∑PBDEs and BDE209inShandong Province were as high as8264.87ng/g and8148.10ng/g, respectively,which is mainly affected by the local PBDEs producing. The high concentrations of∑PBDEs and BDE209in Tianjin were343.88ng/g and329.57ng/g, respectively,which is mainly affected by electronic waste dismantling. BDE209is the predominantcongener in the whole North China, the concentration of which is1-3orders ofmagnitude higher than the other BDE monomer concentrations. This is consistentwith previous studies conducted in China and is consequence of the mass productionand usage of Deca-BDE in the country. The Gaussian diffusion model revealed thatYantai is the point source of BDE47, which is responsible for6.84%(ranging from1.09%to52.08%) of the observed BDE47in soils of North China. Weifang, Yantaiand Jinghai are the point sources of BDE209, which contributed8.44%(ranging from1.38%to65.75%),1.51%(ranging from0.25%to16.36%) and0.55%(ranging from0.07%to6.78%) of BDE209in soils of North China, respectively. The VLIER-HUMAAN model is adopted to calculate the daily PBDEs intakes ofchildren and adults via non-dietary exposure pathways, such as soil/dust ingestion,dermal absorption and particulate inhalation. According to the concentrations ofBDE209, the exposure assessment results show that both non-cancer risk and cancerrisk of children are higher than these of adults. The non-cancer risk and cancer risk ofelectronic waste dismantling region are the moderate. The non-cancer risk and cancerrisk of PBDEs producing region are the high and moderate, respectively. A few ofregions are the low risk, the most of research areas are within acceptable ranges,which indicating that the electronic waste dismantling and PBDEs producing workershave the high PBDEs exposure risk.