New York City subway commuters breathe extremely polluted air that especially endangers the health of black and Hispanic users, a new study shows,
Researchers from New York University discovered that the typical subway platform contained four times the amount of particulate matter (PM2.5) that the Environmental Protection Agency considered safe for a 24-hour period, or nine times the amount recommended by the World Health Organization.
The researchers point out that although while commute time makes just a small percentage of a person’s daily exposure to PM2.5, using the subway contributes significantly to that exposure.
“At that size, these particles penetrate the lung, and it’s been shown that small particles cause issues with cardiovascular, respiratory and neurological diseases,” stated New York University professor of urban systems engineering and main researcher Masoud Ghandehari. “We have 5 million riders per day. Imagine the human impact one may be having in a single day in the New York City subway system.”
Researchers discovered that residents in primarily Black and Hispanic areas as well as low-income New Yorkers commute longer and more frequently by examining census block data for ethnicity and income, raising the exposure to hazardous air contaminants as a result. According to the study, compared to Asian and White commuters, Black and Hispanic workers experience PM2.5 levels that are 35% and 23% higher, respectively.
The researchers discovered a surprising quantity of iron in the small particles they examined, owing primarily to wear and friction from trains’ metal wheels, brakes, and tracks, they added. PM2.5 concentrations were greater in older, busier, deeper stations with inadequate ventilation.