宁波石化工业区周边环境空气中苯系物的分布特征和健康风险评估

Characteristics and health risk of benzene series in atmosphere of petrochemical zone in Ningbo

目的分析宁波石化工业区周边环境空气中的苯系物污染水平、变化特征和污染来源,并进行苯系物对人体健康风险评估。方法利用GC955气相色谱在线分析系统对宁波石化工业区周边环境空气进行在线监测,采集2015年全年数据,并用美国环保局健康风险评估模型对苯系物的人体健康风险进行评估。结果监测期间石化工业区周边环境空气中的苯系物总浓度为17.1μg/m^(3),呈现春季>夏季>秋季>冬季的变化特征。苯系物浓度在一日中呈明显的变化特征,即早晚高峰期间浓度较高、午后相对较低;周末的苯系物浓度高于工作日。苯系物危害指数(HQ)均小于1,表现为苯>二甲苯>甲苯>乙苯。结论本次监测的宁波石化工业区周边环境空气中苯系物浓度以春季和早晚高峰期较高,监测时段内的HQ风险值均在安全范围。

Objective To analyze the concentrations,distribution characteristics and source of benzene series in air of petrochemical zone in Ningbo and to assess health risk. Methods The concentrations of benzene series in air of Ningbo petrochemical zone were determined by GC955 online gas chromatography in 2015,and health risk assessment was performed based on the EPA evaluation model. Results The concentration of total benzene series ranked as spring > summer > autumn >winter,with an average level of 17.1 μg/m^(3),and showed obvious characteristics of daily variation of primary pollutants,such as higher during the morning and evening rush hour and lower in the afternoon,higher at the weekend compared with the working day.The hazard quotient(HQ) of benzene series ranked as benzene >xylene >toluene >ethylbenzene,which were all <1.Conclusion The HQ of benzene series in air of the investigated petrochemical zone in Ningbo are higher in spring and during the morning and evening rush hour,which are safe during monitored periods.