The London Underground: dust and hazards to health
The London Underground: dust and hazards to health
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DOI：
10.1136/oem.2004.014332
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发表时间：
2005-06-01
影响因子：
4.9
通讯作者：
Tran, CL
中科院分区：
文献类型：
--
作者：
Seaton, A;Cherrie, J;Tran, CL
目的：评估伦敦地铁粉尘暴露的危害，为隧道粉尘对工人和出行公众的危害提供知情意见。方法：测量不同地铁站和列车车厢内粉尘的质量浓度(PM2.5)和颗粒物数；分析粉尘的大小和组成；估计工作人员和乘客可能的最大暴露剂量；并进行样品粉尘的体外毒理学试验，并与其他粉尘进行比较。结果：车站站台PM2.5浓度为270-480微克/立方米(3)，颗粒物浓度为14 000-29 000颗粒物/厘米(3)。一个班次的CAB浓度平均为130-200微克/米(3)和17,000-23,000个颗粒物/厘米(3)。粉尘的质量约为67%的氧化铁，1-2%的石英和微量的其他金属，残留物是挥发性物质。最细的颗粒从地表吸入地下，而更粗的尘埃是由刹车、车轮和钢轨相互作用产生的。考虑到暴露的时间，司机和车站工作人员在8小时内的最高暴露剂量约为200微克/立方米(3)；焊接烟雾(如氧化铁)的职业暴露标准是8小时轮班中的5毫克/立方米(3)。毒理学研究表明，高剂量的粉尘具有细胞毒性和炎症潜能，与其主要由氧化铁组成的成分一致。讨论：将PM2.5暴露在地下和地面是不合理的，因为氧化铁和燃烧产生的颗粒物的不良影响不同。地下超细颗粒物的浓度低于地表，而较粗颗粒物(PM2.5)的浓度高于地表。地下的氧化铁浓度远低于工作场所允许的氧化铁浓度，不太可能对工人或通勤者的健康构成重大累积风险。
Aims: To assess hazards associated with exposure to dust in the London Underground railway and to provide an informed opinion on the risks to workers and the travelling public of exposure to tunnel dust.Methods: Concentrations of dust, as mass (PM2.5) and particle number, were measured at different underground stations and in train cabs; its size and composition were analysed; likely maximal exposures of staff and passengers were estimated; and in vitro toxicological testing of sample dusts in comparison with other dusts was performed.Results: Concentrations on station platforms were 270-480 mu g/m(3) PM2.5 and 14 000-29 000 particles/cm(3). Cab concentrations over a shift averaged 130-200 mu g/m(3) and 17 000-23 000 particles/cm(3). The dust comprised by mass approximately 67% iron oxide, 1-2% quartz, and traces of other metals, the residue being volatile matter. The finest particles are drawn underground from the surface while the coarser dust is generated by interaction of brakes, wheels, and rails. Taking account of durations of exposure, drivers and station staff would have maximum exposures of about 200 mu g/m(3) over eight hours; the occupational exposure standard for welding fume, as iron oxide, is 5 mg/m(3) over an eight hour shift. Toxicology showed the dust to have cytotoxic and inflammatory potential at high doses, consistent with its composition largely of iron oxide.Discussion: It is unjustifiable to compare PM2.5 exposure underground with that on the surface, since the adverse effects of iron oxide and combustion generated particles differ. Concentrations of ultrafine particles are lower and of coarser (PM2.5) particles higher underground than on the surface. The concentrations underground are well below allowable workplace concentrations for iron oxide and unlikely to represent a significant cumulative risk to the health of workers or commuters.