PM2.5 on the London Underground
PM2.5 on the London Underground
复制标题
DOI：
10.1016/j.envint.2019.105188
复制
发表时间：
2020-01-01
影响因子：
11.8
通讯作者：
Green, D. C.
中科院分区：
文献类型：
--
作者：
Smith, J. D.;Barratt, B. M.;Green, D. C.
简介：尽管伦敦地铁（LU）每天平均运送280万乘客，但在该地铁系统中发现的富含金属的PM2.5浓度升高的特征和潜在健康影响尚不清楚。方法：开展了空间监测活动，以确定整个LU网络中与健康相关的PM2.5的化学和物理特性，包括日变化和日间变化以及空间分布（地上、地下深度和地铁线路）。为了了解不同站点和不同线路上浓度的相对重要性，我们制作了人口加权的站点PM2.5排名。LU中的PM2.5质量（平均值88 μ g m（-3），中位数28 μ g m（-3））大于周围背景位置（平均值19 μ g m（-3），中值14 μ g m（-3））和伦敦中心的路边环境（平均值22 μ g m（-3），中值14 μ g m（-3））。浓度因线和地点而异，最深和最浅的淹没线是特区（中位数4 μ g m（-3））和维多利亚（中位数361 μ g m（-3），但高达885 μ g m（-3））。与世界各地的其他地铁系统大致一致，采样的LU PM2.5由47%的氧化铁，7%的元素碳，11%的有机碳和14%的金属和矿物氧化物组成。虽然地铁线路深度和地铁列车内部空气质量之间的关系很明显，但与更清洁的外部空气的距离以及车门打开时与车厢空气的交换有明显的影响。乘客人口加权暴露分析证明了一种方法，以确定车站，应优先进行补救，以改善空气quality.Conclusion：在LU的PM2.5浓度比其他伦敦交通环境高出许多倍。因此，在伦敦进行的PM2.5与健康之间关系的流行病学研究中，如果不包括这种环境，很可能会导致大的暴露错误分类。鉴于地下PM2.5对日常暴露的重要贡献，以及与城市PM2.5相比的组成差异，显然需要精心设计的研究，以更好地了解地下暴露对健康的影响。
Introduction: Despite the London Underground (LU) handling on average 2.8 million passenger journeys per day, the characteristics and potential health effects of the elevated concentrations of metal-rich PM2.5 found in this subway system are not well understood.Methods: Spatial monitoring campaigns were carried out to characterise the health-relevant chemical and physical properties of PM2.5 across the LU network, including diurnal and day-to-day variability and spatial distribution (above ground, depth below ground and subway line). Population-weighted station PM2.5 rankings were produced to understand the relative importance of concentrations at different stations and on different lines.Results: The PM2.5 mass in the LU (mean 88 mu g m(-3), median 28 mu g m(-3)) was greater than at ambient background locations (mean 19 mu g m(-3), median 14 mu g m(-3)) and roadside environments in central London (mean 22 mu g m(-3), median 14 mu g m(-3)). Concentrations varied between lines and locations, with the deepest and shallowest submerged lines being the District (median 4 mu g m(-3)) and Victoria (median 361 mu g m(-3) but up to 885 mu g m(-3)). Broadly in agreement with other subway systems around the world, sampled LU PM2.5 comprised 47% iron oxide, 7% elemental carbon, 11% organic carbon, and 14% metallic and mineral oxides. Although a relationship between line depth and air quality inside the tube trains was evident, there were clear influences relating to the distance from cleaner outside air and the exchange with cabin air when the doors open. The passenger population-weighted exposure analysis demonstrated a method to identify stations that should be prioritised for remediation to improve air quality.Conclusion: PM2.5 concentrations in the LU are many times higher than in other London transport Environments. Failure to include this environment in epidemiological studies of the relationship between PM2.5 and health in London is therefore likely to lead to a large exposure misclassification error. Given the significant contribution of underground PM2.5 to daily exposure, and the differences in composition compared to urban PM2.5, there is a clear need for well-designed studies to better understand the health effects of underground exposure.