Abstract

Objectives:

The goals of this study were to assess the air quality in subway systems in the northeastern United States and estimate the health risks for transit workers and commuters.

Methods:

We report real-time and gravimetric ${\mathrm{PM}}_{2.5}$ concentrations and particle composition from area samples collected in the subways of Philadelphia, Pennsylvania; Boston, Massachusetts; New York City, New York/New Jersey (NYC/NJ); and Washington, District of Columbia. A total of 71 stations across 12 transit lines were monitored during morning and evening rush hours.

Results:

We observed variable and high ${\mathrm{PM}}_{2.5}$ concentrations for on-train and on-platform measurements during morning (from 0600 hours to 1000 hours) and evening (from 1500 hours to 1900 hours) rush hour across cities. Mean real-time ${\mathrm{PM}}_{2.5}$ concentrations in underground stations were $779\pm 249$, $548\pm 207$, $341\pm 147$, $327\pm 136$, and $112\pm 46.7{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$ for the PATH-NYC/NJ; MTA-NYC; Washington, DC; Boston; and Philadelphia transit systems, respectively. In contrast, the mean real-time ambient ${\mathrm{PM}}_{2.5}$ concentration taken above ground outside the subway stations of PATH-NYC/NJ; MTA-NYC; Washington, DC; Boston; and Philadelphia were $20.8\pm 9.3$, $24.1\pm 9.3$, $12.01\pm 7.8$, $10.0\pm 2.7$, and $12.6\pm 12.6{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$, respectively. Stations serviced by the PATH-NYC/NJ system had the highest mean gravimetric ${\mathrm{PM}}_{2.5}$ concentration, $\mathrm{1,020}{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$, ever reported for a subway system, including two 1-h gravimetric ${\mathrm{PM}}_{2.5}$ values of approximately $\mathrm{1,700}{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$ during rush hour at one PATH-NYC/NJ subway station. Iron and total carbon accounted for approximately 80% of the ${\mathrm{PM}}_{2.5}$ mass in a targeted subset of systems and stations.

Discussion:

Our results document that there is an elevation in the ${\mathrm{PM}}_{2.5}$ concentrations across subway systems in the major urban centers of Northeastern United States during rush hours. Concentrations in some subway stations suggest that transit workers and commuters may be at increased risk according to U.S. federal environmental and occupational guidelines, depending on duration of exposure. This concern is highest for the ${\mathrm{PM}}_{2.5}$ concentrations encountered in the PATH-NYC/NJ transit system. Further research is urgently needed to identify the sources of ${\mathrm{PM}}_{2.5}$ and factors that contribute to high levels in individual stations and lines and to assess their potential health impacts on workers and/or commuters. https://doi.org/10.1289/EHP7202

中文翻译：

---

美国东北部地铁系统 PM2.5 浓度及成分

摘要

目标：

本研究的目标是评估美国东北部地铁系统的空气质量，并评估交通工人和通勤者的健康风险。

方法：

我们报告实时和重量 ${\mathrm{下午}}_{2.5}$宾夕法尼亚州费城地铁收集的区域样本的浓度和颗粒成分；马萨诸塞州波士顿；纽约市，纽约/新泽西（NYC/NJ）；和华盛顿哥伦比亚特区。在早晚高峰时段，共监测了 12 条公交线路的 71 个车站。

结果：

我们观察到变量和高 ${\mathrm{下午}}_{2.5}$在早上（从 0600 小时到 1000 小时）和晚上（从 1500 小时到 1900 小时）高峰时间跨城市的火车上和站台测量的浓度。平均实时${\mathrm{下午}}_{2.5}$ 地铁站的浓度为 $779\pm 249$, $548\pm 207$, $341\pm 147$, $327\pm 136$， 和 $112\pm 46.7{\mathrm{\mu }\mathrm{G}/\mathrm{米}}^3$PATH-NYC/NJ；MTA-纽约；华盛顿特区; 波士顿；和费城交通系统，分别。相比之下，平均实时环境${\mathrm{下午}}_{2.5}$PATH-NYC/NJ 地铁站外的地面集中；MTA-纽约；华盛顿特区; 波士顿；和费城$20.8\pm 9.3$, $24.1\pm 9.3$, $12.01\pm 7.8$, $10.0\pm 2.7$， 和 $12.6\pm 12.6{\mathrm{\mu }\mathrm{G}/\mathrm{米}}^3$， 分别。PATH-NYC/NJ 系统服务的站点的平均重力测量值最高${\mathrm{下午}}_{2.5}$ 专注， $\mathrm{1,020}{\mathrm{\mu }\mathrm{G}/\mathrm{米}}^3$, 曾经报道过地铁系统，包括两个 1 小时重力测量 ${\mathrm{下午}}_{2.5}$ 大约值 $\mathrm{1,700}{\mathrm{\mu }\mathrm{G}/\mathrm{米}}^3$在 PATH-NYC/NJ 地铁站的高峰时段。铁和总碳约占总碳的 80%${\mathrm{下午}}_{2.5}$ 系统和站的目标子集中的质量。

讨论：

我们的结果表明，在 ${\mathrm{下午}}_{2.5}$在高峰时段，美国东北部主要城市中心的地铁系统的浓度。根据美国联邦环境和职业指南，一些地铁站的浓度表明，根据暴露时间的长短，交通工人和通勤者可能面临更高的风险。这种担忧对${\mathrm{下午}}_{2.5}$PATH-NYC/NJ 交通系统中遇到的浓度。迫切需要进一步研究以确定其来源${\mathrm{下午}}_{2.5}$和导致个别车站和线路高水平的因素，并评估它们对工人和/或通勤者的潜在健康影响。https://doi.org/10.1289/EHP7202