10 Journal of Urban Health: Bulletin of the New York Academy of Medicine, Vol. 82, No. 1, doi:10.1093/jurban/jti004  The Author 2005. Published by Oxford University Press on behalf of the New York Academy of Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oupjournals.org Advance Access publication February 28, 2005 SPECIAL FEATURE: MASS TRANSIT Health and Safety Hazards Associated with Subways: A Review R. R. M. Gershon, K. A. Qureshi, M. A. Barrera, M. J. Erwin, and F. Goldsmith ABSTRACT Subway systems are key components in mass transportation networks worldwide, providing rapid and affordable transportation to urban communities in 58 different countries. The benefits afforded by subway transit are numerous and mainly derived from the reduction in automobile use, thereby limiting environmental and health hazards associated with exhaust-air emissions. Additionally, by limiting congestion and providing vital transportation links within a city, subways also improve the overall quality of life of urban communities. However, to best maximize the positive impact on the urban environment, subway systems need to provide a safe and healthy environment for both passengers and subway transit workers. Periodically, safety concerns are raised, most recently in relation to the vulnerability of subways to terrorist attacks. To examine this issue more carefully, we conducted a structured review of the literature to identify and characterize potential health and safety hazards associated with subways. A secondary goal was to identify various risk management strategies designed to minimize the risk of these hazards. This information may be helpful to urban communities, urban planners, public health specialists, and others interested in subway safety. KEYWORDS Mass Transit, Safety and Health, Subway Riders, Subway Transportation, Transit Workers. INTRODUCTION The US mass transportation network relies heavily on rail systems, two of which are particularly important in the urban setting: subways and commuter rail systems. Subways, also referred to as metro, heavy rail, or rapid rail, operate, for the most part, within a metropolitan area, whereas commuter rail systems (also known as suburban or regional rail) operate between a city and the outlying suburbs. 1 Both have a long history tied to the development of urban centers. In the United States, for example, explosive urban population growth in the 1880s led to the develop- ment of the first US subway system, which was constructed in Boston in 1897, soon followed, in 1904, by the first New York City subway line. 2 There are now 14 different subway transit system agencies in the United States providing service to 11 different metropolitan areas, with a new system planned for Puerto Rico. 3 Dr. Gershon, Dr. Qureshi, Ms. Barrera, and Ms. Erwin are with the Mailman School of Public Health, Columbia University, New York, NY; Dr. Goldsmith is with the Transit Workers Union Local, New York, NY. Correspondence: Robyn R. M. Gershon, DrPH, Mailman School of Public Health, Columbia University, 600 West 168th Street, 4th Floor, New York, NY 10032. (E-mail: rg405@columbia.edu)