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News Releases from Region 05

EPA Study Finds Elevated Particulate Levels in Air on Train Platforms at Chicago Union Station

Contact Information: 
Joshua Singer (singer.joshua@epa.gov)

For Immediate Release No. 15-OPA163

CHICAGO (November 5, 2015)-- The U.S. Environmental Protection Agency today released an air quality study that documents elevated concentrations of particulate matter (PM2.5) in ambient air on train platforms at Union Station in Chicago. The concentration of PM2.5 in air on the train platforms was 23 - 96 percent higher than concentrations recorded on nearby streets on the days that monitoring was conducted last summer. The study also found that the highest concentrations of PM2.5 occur during rush hours. Higher particulate concentrations were found at the south platforms than at the north platforms, and particulate levels are highest near locomotives.

PM2.5 is a mixture of small particles (2.5 micrometers in diameter and smaller) and liquid droplets. When inhaled, fine particles can reach deep into the lungs and may enter the bloodstream. Inhaling PM2.5 can cause serious health effects - especially for young people, the elderly and those with respiratory diseases such as asthma. Diesel exhaust from locomotives also contains carbon monoxide, benzene, formaldehyde, nitrogen oxides and other harmful pollutants.

EPA studied air quality at Union Station over a three week period during June and July 2015. Scientists used portable air monitors on publicly accessible platforms to measure concentrations of PM2.5 in the air at various times between 6 a.m. and 6 p.m. EPA took similar measurements at street level near the station. EPA conducted 64 platform tests and 35 background tests.

EPA is discussing the results of the study with Metra, Amtrak and representatives of several buildings with ventilation systems that impact air quality at Union Station. Short-term options to improve air quality on the train platforms include optimizing the existing ventilation systems above Union Station and changing operational procedures. Long-term options include installation of additional ventilation systems and measures to reduce particulate emissions.

More information on the Union Station air study can be found at: