生活垃圾填埋场细菌气溶胶分布及职业暴露风险评估

Distribution and occupational exposure risk assessment of bacterial aerosols at a sanitary landfill site

为探究生活垃圾填埋场细菌气溶胶分布以及场区员工的职业暴露风险,在西安市某垃圾填埋场的6个功能区测定和分析了细菌气溶胶浓度、粒径分布和细菌活性,并运用风险商法评估场区员工的职业暴露风险.结果表明,生活垃圾填埋场细菌气溶胶浓度最高和最低值分别为渗滤液收集区((5381±3875)CFU·m^(-3))和生活办公区((1227±204)CFU·m^(-3)),不同季节细菌气溶胶浓度变化为:夏季>秋季>冬季>春季.各采样点位于0.65~1.1μm的细菌气溶胶浓度最低,小粒径细菌气溶胶比重由春季到冬季逐渐增大,各采样点细菌气溶胶的平均中值粒径均小于5.0μm.流式细胞术分析结果显示,冬季不同采样点细菌气溶胶中活菌占比为74%~83%.细菌气溶胶职业暴露风险商均小于1,不同季节的暴露风险大小为夏季>秋季>冬季>春季,成年男性的职业暴露风险大于成年女性.

In order to evaluate the distribution and occupational exposure risk of bacterial aerosols form sanitary landfills,the concentrations,particle sizes distribution and viability of bacterial aerosols were measured and analyzed at six functional regions of a sanitary landfill site in Xi′an.The risk quotient was employed to evaluate the occupational exposure risk.The results showed that the highest and lowest concentrations of bacterial aerosols at the sanitary landfill site were recorded at the leachate collection area((5381±3875)CFU·m^(-3))and the office area((1227±204)CFU·m^(-3)),respectively.Dynamics of bacterial aerosol concentrations in different seasons followed the ranking order summer>autumn>winter>spring.Bacterial aerosols with particle sizes ranging from 0.65 to 1.1μm were at the lowest concentration at each sampling site.Also,the proportion of small⁃sized bacterial aerosols increased gradually from spring to winter.The average median diameter of bacterial aerosols at each sampling site was less than 5.0μm.Flow cytometry analysis demonstrated that the proportion of viable bacterial aerosols at each sampling site fluctuated within the range of 74%to 83%in winter.The occupational exposure risk quotients of bacterial aerosols were less than 1 in the sampling period,but the value of risk quotients were as follows:summer>autumn>winter>spring.Moreover,the occupational exposure risk was distinguishable by gender with the risk of males being higher than that of females.