天津采暖期大气PM_(2.5)中重金属元素污染及其生态风险评价

The pollution characteristics and potential ecological risk of heavy metals in PM_(2.5) during heating season in Tianjin

为揭示天津地区大气中重金属污染的潜在风险,分析了天津采暖期城区和武清大气PM2.5中重金属元素水平,并分别采用富集因子法和潜在生态风险指数法对重金属污染风险进行了评价.结果表明,天津城区大气PM2.5中重金属元素的浓度水平排序为Zn>Ti>Mn>Pb>Cu>Cr>Co>As>Cd>Hg,武清则为Zn>Ti>Pb>Mn>Cr>Cu>Co>As>Cd>Hg;Cu,Zn,Pb和Cd等元素的富集因子高于10,表明其系人为污染元素;重金属元素污染评价显示Ti和Mn基本无污染,As、Cr、Co等元素存在一定污染,Cu、Zn、Pb和Cd等元素潜在生态风险高,Cd生态危害程度极强,总体潜在生态风险指数分别为1381.1(城区)和1251.1(武清),达到极强程度.

To explore the pollution characteristics and the potential ecological risk of heavy metals in PM2.5 of Tianjin, the main heavy metals such as Zn, Ti, Mn, Pb, Cu, Cr, Co, As, Cd and Hg were detected, and the pollution status was evaluated with enrichment factors and Hakanson potential ecological risk index, respectively. The results showed that the pollution degree of the heavy metals followed the order Zn〉Ti〉Mn〉Pb〉Cu〉Cr〉Co〉As〉Cd〉Hg at the urban and Zn〉Ti 〉Pb 〉Mn〉Cr〉Cu〉Co〉As〉Cd〉Hg at Wuqing. The ecological risk assessment of heavy metals showed that the ecological risk of Ti and Mn were basically pollution-free. As, Cr and Co existed certain pollution. The potential ecological risk of Cu, Zn, Pb and Cd was high, while ecological harm degree of Cd was extremely strong, the whole potential ecological risk degree （1381.1at the urban and 1251.1at Wuqing） was very strong.