The management of electronic waste(e-waste),which can be a source of both useful materials and toxic substances,depending on the processing method,is important for promoting material cycling.In this study,we used the ...The management of electronic waste(e-waste),which can be a source of both useful materials and toxic substances,depending on the processing method,is important for promoting material cycling.In this study,we used the dioxin-responsive chemical-activated luciferase gene expression(DR-CALUX)assay combined with gas chromatographyehigh-resolution mass spectrometry to evaluate the levels of dioxin-like compounds in surface soils and river sediments collected in and around an e-waste-processing village in northern Vietnam.The WHO-TEQs(Toxic equivalents)of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),coplanar polychlorinated biphenyls(Co-PCBs),and polybrominated dibenzo-pdioxins and dibenzofurans(PBDD/Fs)in soils collected in January 2012 ranged from 0.29 to 310 pg/g(median 2.9 pg/g,n=32),and the WHO-TEQs in sediments ranged from 0.96 to 58 pg/g(median 4.4 pg/g,n=8).Dioxin-like activities(CALUX-TEQs[2,3,7,8-TCDD equivalent])in soils collected in January 2012,2013,and 2014 ranged from<30 to 4300 pg/g(median<30 pg/g,n=96),and the activities in sediments ranged from<30 to 4000 pg/g(median 33 pg/g,n=24).Dioxin-like compounds accumulated in samples collected around e-waste-processing areas such as open-burning sites and e-waste-processing workshops,and the compounds may be transported from their sources to surrounding areas over the course of several years.Some of the CALUX-TEQs,but not WHO-TEQs,values were higher than the maximum acceptable WHO-TEQs promulgated by various authorities,indicating that all dioxin-like compounds should be evaluated in samples collected from e-waste-processing areas.Our findings suggest that open burning and open storage of e-waste should be prohibited and that wastewater treatment should be implemented at each workshop to reduce contamination by dioxin-like compounds from e-waste.展开更多
Inappropriate e-waste-processing operation is a serious issue in developing countries since the early 2000's.Field research was conducted to clarify its influences and diffuse toxic substances in the environment a...Inappropriate e-waste-processing operation is a serious issue in developing countries since the early 2000's.Field research was conducted to clarify its influences and diffuse toxic substances in the environment at e-waste-processing sites in a village in northern Vietnam from 2012 to 2014.We investigated surface soil samples collected from e-waste-processing sites,open burning sites,and rice paddy sites.Sediment samples and water samples were also collected from a river that runs through the village.The hazardous metal concentration in soil and river sediment samples indicated that 7 elements(Ca,Cu,Mo,Ni,Pb,Sn,and Zn)had high concentrations as a result of e-waste-processing.Most notably,Pb and Cu had high concentrations in soil samples(Pb:26e2200 mg/kg,Cu:22e3000 mg/kg).The results of a multivariate analysis indicated that these 7 elements were closely correlated with e-waste-processing.Concentrations of hazardous metals showed an upward trend where e-waste-processing occurred during the 3-year study period,although it was not significant statistically at present.Open burning activity had a great influence on Cu accumulation,and maximum Cu concentrations increased from 340 mg/kg in 2012e3000 mg/kg in 2014 in soil samples from open-burning sites.There were large differences in the dominant hazardous metal depending on the type of e-waste-processing workshop because hazardous metal composition was influenced by the types of e-waste and the processing procedures.It is necessary to avoid e-waste processing in open-air environment to control emissions of hazardous substances.Especially,open burning should be prohibited.展开更多
基金supported by the Society for the Promotion of Science and Environment Research and Technology Development Fund(no.3K133010 and no.3K153001)of the Ministry of the Environment,Japansupported by the Ministry of Education,Culture,Sports,Science and Technology,Japan(MEXT)to a project on Center of Excellence for Cooperative and Collaborative Studies e Leading Academia in Marine and Environmental Research(LaMer).
文摘The management of electronic waste(e-waste),which can be a source of both useful materials and toxic substances,depending on the processing method,is important for promoting material cycling.In this study,we used the dioxin-responsive chemical-activated luciferase gene expression(DR-CALUX)assay combined with gas chromatographyehigh-resolution mass spectrometry to evaluate the levels of dioxin-like compounds in surface soils and river sediments collected in and around an e-waste-processing village in northern Vietnam.The WHO-TEQs(Toxic equivalents)of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),coplanar polychlorinated biphenyls(Co-PCBs),and polybrominated dibenzo-pdioxins and dibenzofurans(PBDD/Fs)in soils collected in January 2012 ranged from 0.29 to 310 pg/g(median 2.9 pg/g,n=32),and the WHO-TEQs in sediments ranged from 0.96 to 58 pg/g(median 4.4 pg/g,n=8).Dioxin-like activities(CALUX-TEQs[2,3,7,8-TCDD equivalent])in soils collected in January 2012,2013,and 2014 ranged from<30 to 4300 pg/g(median<30 pg/g,n=96),and the activities in sediments ranged from<30 to 4000 pg/g(median 33 pg/g,n=24).Dioxin-like compounds accumulated in samples collected around e-waste-processing areas such as open-burning sites and e-waste-processing workshops,and the compounds may be transported from their sources to surrounding areas over the course of several years.Some of the CALUX-TEQs,but not WHO-TEQs,values were higher than the maximum acceptable WHO-TEQs promulgated by various authorities,indicating that all dioxin-like compounds should be evaluated in samples collected from e-waste-processing areas.Our findings suggest that open burning and open storage of e-waste should be prohibited and that wastewater treatment should be implemented at each workshop to reduce contamination by dioxin-like compounds from e-waste.
文摘Inappropriate e-waste-processing operation is a serious issue in developing countries since the early 2000's.Field research was conducted to clarify its influences and diffuse toxic substances in the environment at e-waste-processing sites in a village in northern Vietnam from 2012 to 2014.We investigated surface soil samples collected from e-waste-processing sites,open burning sites,and rice paddy sites.Sediment samples and water samples were also collected from a river that runs through the village.The hazardous metal concentration in soil and river sediment samples indicated that 7 elements(Ca,Cu,Mo,Ni,Pb,Sn,and Zn)had high concentrations as a result of e-waste-processing.Most notably,Pb and Cu had high concentrations in soil samples(Pb:26e2200 mg/kg,Cu:22e3000 mg/kg).The results of a multivariate analysis indicated that these 7 elements were closely correlated with e-waste-processing.Concentrations of hazardous metals showed an upward trend where e-waste-processing occurred during the 3-year study period,although it was not significant statistically at present.Open burning activity had a great influence on Cu accumulation,and maximum Cu concentrations increased from 340 mg/kg in 2012e3000 mg/kg in 2014 in soil samples from open-burning sites.There were large differences in the dominant hazardous metal depending on the type of e-waste-processing workshop because hazardous metal composition was influenced by the types of e-waste and the processing procedures.It is necessary to avoid e-waste processing in open-air environment to control emissions of hazardous substances.Especially,open burning should be prohibited.