摘要:
初步研究了四川省卧龙地区5个不同海拔高度的表层土壤和2个牦牛样品中二噁英/呋喃(PCDD/Fs)、共平面多氯联苯(co-PCBs)和多氯萘(PCNs)的分布特征、来源、毒性当量以及生态风险状况.土壤样品中总2,3,7,8-PCDD/Fs的含量范围为2.48—4.30 pg·g-1dw,平均3.50 pg·g-1dw,最高含量在海拔3927 m的塘房.co-PCBs的总含量平均为9.14 pg·g-1dw,最高值在海拔4487 m的垭口.总2,3,7,8-PC-DD/Fs和总co-PCBs含量随海拔高度的变化表现出正相关关系.不同海拔高度土壤中的PCDD/Fs和co-PCBs异构体的分布相似,表明具有相同的来源.总PCNs与海拔梯度呈负相关关系,最高含量出现在海拔3345 m的贝母坪,平均21.4 pg·g-1dw,主要以3-氯为主.土壤中PCDD/Fs毒性当量浓度范围为0.29—0.43pg TEQ·g-1dw.牦牛肉和牦牛组织中PCDD/Fs总浓度分别为27.5和23.6 pg.g-1脂肪,毒性当量浓度为4.04和4.07 pg TEQ·g-1脂肪.结果表明,牦牛中的PCDD/Fs,co-PCBs和PCNs不大可能对卧龙地区人群导致严重的负面效应.
Abstract:
Five of top soils and two yak samples were collected from Wolong area and analyzed to determine the concentration levels,altitude distribution,sources,and toxicity equivalency quantity(TEQ)of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),co-planar polychlorinated biphenyls(co-PCBs)and polychlorinated naphthalenes(PCNs).The total PCDD/Fs concentrations in the top soils ranged between 2.48—4.30 pg·g-1 dw,averaging 3.50 pg·g-1 dw with the highest concentration at 3927 m altitude.The total co-PCBs concentrations averaging 9.14 pg·g-1 dw with the highest concentration at 4487 m altitude.The total 2,3,7,8-PCDD/Fs and total co-PCBs concentrations showed positive co-relationships with altitude.The congener profiles of both 2,3,7,8-PCDD/Fs and co-PCBs at different altitudes showed similar patterns,suggesting similar sources.The total PCNs,averaging 21.4 pg·g-1 dw showed a negative co-relationship with altitude,with the highest concentration at 3345 m altitude.The total PCNs is dominated by tri-CNs.The atmospheric transportation is likely the sources for them.The PCDD/Fs-TEQ in the soils were in the range of 0.29—0.43 pg·g-1 dw.The total concentrations of PCDD/Fs in the yak meat and tissue were 27.5 and 23.6 pg·g-1 lipid,respectively,while the PCDD/Fs-TEQ in the yak meat and tissue were 4.04 and 4.07 pg TEQ·g-1 lipidrespectively,which is unlikely to cause adverse health effect to the yak-meat consuming people.