上海某地铁站黑碳浓度水平及个体暴露特征

基于对职业环境空气污染物的个体暴露风险关注,在上海某地铁站进行了ρ(黑碳)的连续定点(新风井和车辆控制室)监测；同时对地铁工作人员进行个体黑碳暴露采样,并与定点监测的ρ(黑碳)比较,探讨个体采样在黑碳暴露研究中的作用. 结果表明:某地铁站新风井处ρ(黑碳)与ρ(NO₂)呈显著相关(R=0.75,P<0.05),而与ρ(PM₁₀)无显著相关性(R=0.43,P>0.1)；由ρ(黑碳)日变化及其在工作日和休息日的差异可知,地铁站内ρ(黑碳)可能与室外机动车尾气排放相关；与定点监测结果不同,个体黑碳暴露浓度波动范围大,出现了未在定点监测中观测到的极高值,并且个体黑碳暴露浓度的四分位差值(IQR)是定点监测结果的2倍；尽管车控室内平均个体黑碳暴露浓度较低,但由于个体72%的工作时间是在车控室内度过的,因此车控室的个体黑碳暴露剂量比非车控室环境高. 

Concentration Levels and Personal Exposure Characteristics of Black Carbon in a Shanghai Subway Station

Given increased attention to the risks from occupational exposure to air pollutants, we continuously monitored the level of black carbon(BC) at two fixed sites(air intake site and dispatcher office) at a Shanghai subway station. We also made a personal sampling of BC for workers at the station. The importance of personal sampling in assessing the risk of BC exposure was investigated by comparing the BC concentrations with those at fixed sites. The results indicated that the mass concentration of BC at the air intake site were strongly correlated with mass concentration of NO₂ (Spearman correlation coefficient Rwas 0.75, P<0.05), but no significant correlation was found with mass concentration of PM₁₀(R=0.43, P>0.1). Considering the daily changes of mass concentration of BC and the differences between weekdays and weekends, we concluded that the indoor mass concentration of BC was probably associated with outdoor vehicle exhaust emissions. In contrast with the results of the fixed site monitoring, large variations and extremely high mass concentration of BC were observed in the personal exposure data. Furthermore, the interquartile range(IQR) of personal exposure to BC was nearly twice as large as that of the fixed site BC. The comparison of personal exposure BC levels between non-office and office environments showed that personal exposure of BC was lower in the office environment; however, the exposure dose of personal BC was higher in the office than that in non-office environments because subjects spent approximately 72% of their workday in the office environment.