
New York subway platform pollution is 10 times higher than safe level, study finds
A new study has found that New York subway riders are breathing in “exceptionally high” levels of hazardous air.
The subway system accommodates 5.5 million commuters every day and some of them are being exposed to more pollution than others.

‘Exceptionally high’ pollution on New York subway
The study, conducted by researchers at New York University and published in the PLOS One journal, studied 3.1 million workers across four boroughs of New York City: Manhattan, Brooklyn, Queens and The Bronx.
They analyzed the levels of a dangerous fine-particle air pollution called PM2.5 on platforms and inside train cabins and found it is “exceptionally high” in both areas. PM2.5 is particulate matter that is less than 2.5 micrometres in diameter.
The average concentration of pollution on underground platforms in the city was 139 �g/m3 (micrograms per cubic meter air), which is 10 times the 24-hour guideline set by the World Health Organization (WHO). This deems how much PM2.5 is safe for a human to breathe in within 24 hours.
In comparison the average amount of particle matter on trains when underground was 99 �g/m3, which is seven times the WHO safe guideline. The WHO says that 24-hour average exposures should not exceed 15 �g/m3.
Particulate matter refers to a mixture of solid particles and liquid droplets that are found in the air. They can get deep into your lungs and even into your bloodstream, causing serious health problems, the United States Environmental Protection Agency (EPA) explains.
This includes premature death in people with heart or lung disease, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and increased respiratory symptoms such as coughing or difficulty breathing.

Blacks and Hispanics experience higher pollution
The study also found that Black people experience 35% higher PM2.5 exposure compared to Asian and White workers. Hispanic workers also breathe in 23% higher pollution. This is caused by the difference in commuting patterns among subway users.
Researchers discovered that pollution can “significantly differ” based on the specific route taken and the stations encountered along the way. Workers have different origins and destinations, resulting in varying levels of PM2.5 exposure.
Those with longer commutes or people who transfer between lines spend more time on the subway, potentially leading to increased exposure to air pollution. Some stations have higher PM2.5 concentrations than others, so those who use them will also have increased exposure.
People living in low-income communities tend to rely on the subway more, so socioeconomic factors play a big role in exposure to pollution.