山西省典型燃煤污染区土壤中多环芳烃风险评价

Polycyclic Aromatic Hydrocarbons Pollution and Risk Assessment in Soil of Typical Coal-fired Pollution Region in Shanxi Province

在山西省临汾市南部燃煤污染代表性区域(1034 km^2)采集了128个表层土壤样品,采用气相色谱-质谱联用技术(GC-MS)分析了土壤中16种优控多环芳烃(PAHs)的含量,并对样品中PAHs的生态风险和人体健康风险进行了评价。结果显示,16种PAHs的质量分数为(723.2±1 230)μg·kg^(-1),组成成分以4~6环为主。根据Maliszewska-Kordybach分级评价标准,研究区域土壤中78.12%的样品受到PAHs不同程度的污染。基于内梅罗综合污染指数法评价结果,研究区域83.59%的样点存在PAHs污染,其中古城镇和新城镇60%以上的采样点达到了重度污染级别。基于毒性当量因子(Toxic Equivalency Factor,TEF)风险评价法的生态风险评价结果显示,荷兰土壤质量标准所涉及到的10种PAHs的苯并(a)芘(Bap)毒性当量浓度(Bap toxic equivalent quantity,TEQ_(Bap))为(67.50±137.7)μg·kg^(-1),其中42.19%的样点超过荷兰土壤TEQ_(Bap10)的标准限值,古城镇和新城镇土壤中PAHs平均超标3倍以上。对研究区域的暴露人群分别进行非致癌风险及致癌风险评价,结果显示研究区域土壤中的PAHs不会对成人和儿童产生明显的非致癌风险。而在古城镇、新城镇、陶寺乡、景毛乡和永固乡,土壤中PAHs引起的综合致癌风险已超过可接受致癌风险(10^(-6)),对人群健康构成了潜在威胁,需引起重视;其他研究区域的致癌风险仍在可接受范围(10^(-6))之内。

To investigate the pollution,ecological risk,and health risk of PAHs,GC-MS was adopted to analysis the concentration of16 priority polycyclic aromatic hydrocarbons（PAHs） which were measured in 128 surface soil samples from typical coal-fired pollution region in Shanxi Province.The results showed that the total mass concentration of these PAHs were（723.2±1 230） μg·kg-（-1）.Four to six rings PAHs contributed most of total PAH burden.According to Maliszewska-Kordybach＇s classification standards of soil contamination,78.12%of samples were contamined in different degree.Based on Nemerow Pollution Index,the classification evaluation showed that 83.59%soil samples were polluted.Gucheng Town and Xincheng Town were the most heavily polluted area,over 60%soil samples were heavily polluted by PAHs.Considering the different toxicity in PAHs monomer,toxic equivalence factors（TEFs） were used for valuing PAHs ecological risk.The results showed Bap toxic equivalent quantity（TEQ_（Bap）） of 10 PAHs in the Dutch soil standard were（67.50±137.7） μg·kg-（-1）,42.19%of samples in which were higher than Dutch target values.Gucheng Town and Xincheng Town were the most heavily toxic contamination area,exceed multiple was above 3 times,averagely.Both for adult and children,PAHs in the soil of studied region were unlikely to pose a significant non-carcinogenic risk.Moreover,the total cancer risk（CK_（total）） exceeded acceptable levels（10-（-6）） in Gucheng,Xincheng,suggesting the soil PAHs of these areas may cause harm to human health and should be paid more attention.