天津市大气重污染天气下细颗粒物中重金属污染特征及健康风险评估

Pollution characteristics and health risk assessment of heavy metals in fine particles with different levels of air pollution in Tianjin

目的了解2016年天津市重污染(空气质量指数,air quality index,AQI>200)天气情况下,细颗粒物中重金属的污染水平和对健康的影响。方法对天津市和平区和北辰区冬季采暖期的大气进行采样,共采集159份样品,用电感耦合等离子体质谱仪对9种金属元素进行测定。用美国环境保护署的健康风险评价模型对人群终生超额危险度及终生患癌超额危险度的健康风险进行评估。结果AQI>200的天气细颗粒物的平均质量浓度最大值出现在12月份为0.588 mg/m^3,超过国家标准二级浓度限值的7.8倍,市区和市郊砷对成人的致癌超额危险度最大值分别为:8.62×10^(-6)和9.10×10^(-6)。市区和市郊对儿童的致癌超额危险度的范围为3.40×10^(-8)~4.09×10^(-6),对成人的非致癌危险度为9.17×10^(-4)~6.56×10^(-2),对儿童的非致癌危险度为1.49×10^(-4)~8.85×10^(-2),均小于1。结论AQI>200的天气细颗粒物中砷带来的健康风险最高,相关部门在制订风险管理政策时应引起重视。

Objective To explore the pollution levels and health effects of heavy metals in fine paniculate matter under the weather conditions （ air quality index, AQI 〉 200） of Tianjin in 2016. Methods Regular sampling of the atmosphere of the winter heating season was conducted in Heping District and Beichen District of Tianjin. A total of 159 samples were collected. Sb, As, Cd, Cr, Hg, Pb, Mn, Ni and Se were identified using a 7 500cx inductively coupled plasma mass spectrometer. Health risk of respiratory exposure to carcinogenic and noncarcinogenic heavy metal was assessed through the United States Environmental Protection Agency health risk assessment model. Results The amount of 41 samples was obtained in 21 days of AQI〉200, and 118 samples in 59 days of AQI〈200. The average value of the average mass concentration of 0. 588 mg/m^3 in December, which was 7.8 times of the national secondary standard concentration limited. The sequence of the concentrations of the nine heavy metals in the two weather lined from high to low was the constant ones ： Pb, Mn, As, Sb, Se, Cd, Cr, Ni, Hg. When the AQI〉200, the excess carcinogenic risk of As for adults were 8.62 × 10^-6 and 9. 10 × 10^-6 in urban and suburban respectively. The range of carcinogenic excess risk for children in urban areas and suburbs was from 3.40 × 10^-8 to 4. 09 × 10^-6, The non-carcinogenic risk to adults ranged from 9.17 × 10^-4 to 6. 56 × 10^-2, and the non-carcinogenic risk to children ranged from 1.49 × 10^-4 to 8. 85 × 10^-2, both less than 1.ConclusionAs has the highest health risk when AQI〉200. Relevant departments in the development of risk management policies should pay greater attention.