The air high quality within the Metropolis Corridor subway station in downtown Philadelphia is far worse than on the sidewalks straight above the station. That may be a key discovering of our new examine revealed within the Journal of Publicity Science & Environmental Epidemiology.
We’re an environmental scientist and a biochemist who assessed the air high quality on the fifteenth Road-Metropolis Corridor station in Philadelphia. We targeted on this station as a result of our earlier examine discovered it to have the best ranges of particulate matter amongst 12 Philly subway stations we measured on the busy Market-Frankford or Broad Road traces.
Most regarding, we discovered that there was about 10 occasions extra black carbon contained in the station than at road stage. Black carbon, which is often known as soot, is a serious part of tremendous particulate air air pollution. It’s emitted from incomplete combustion of fossil fuels and biomass burning, and inhaling it’s related to hostile well being results equivalent to bronchial asthma, coronary heart assaults and lung most cancers.
Our findings recommend that the black carbon is being generated by the subway system itself. Graphite used on brake pads is one potential supply.
We additionally discovered that ranges of ultrafine particles, or UFP, had been about 1.7 occasions greater underground than above floor. Whereas tremendous particles are as much as 2.5 microns in diameter – about 35 occasions smaller than a grain of tremendous seashore sand – ultrafine particles are 0.1 microns or smaller. These particles are regarding, as they penetrate deep into folks’s lungs.
Restricted entry to outdoors air, the frequency of trains, a lot of passengers and its location within the coronary heart of Heart Metropolis could also be among the causes for the excessive concentrations of particulate matter on the fifteenth Road station.
Subway air high quality has beforehand been investigated in Philadelphia and a number of other different U.S. cities, together with Boston, New York Metropolis and Washington, D.C. A examine of 71 subway stations in these metro areas discovered PATH stations in New York and New Jersey to have the best focus of tremendous particles. That examine additionally discovered the same focus of tremendous particles, primarily iron and carbon, in Philadelphia as we discovered.
Our examine, nonetheless, measured extra varieties and sizes of particulate matter.
This subway station has the worst air high quality in Philly, researchers discovered.
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Why it issues
Our examine highlights the necessity for Philadelphia to observe the air high quality in its subways and to scale back air air pollution publicity for commuters and subway employees.
A number of main components contribute to subway air air pollution. These embrace the subway system’s age, how worn the wheels and rails are, the frequency of trains, the usage of a graphite lubricant on the brake pads, poor air flow, station depth and the boundaries of entry to outside air and outside site visitors.
Having higher air flow, utilizing platform display screen doorways and cleansing extra usually to reduce mud are just a few methods to enhance air high quality.
Whereas we consider air high quality within the subway must be improved, our findings don’t recommend that commuters ought to keep away from taking the subway. Air air pollution ranges are extremely variable throughout stations and over time, and commuters spend comparatively brief intervals of time inside subway stations.
Folks with any well being issues, particularly a lung situation, can get glorious safety by sporting an N95 masks or perhaps a surgical masks. Subway employees can use air purifiers to scale back their publicity to particle air pollution.
How we do our work
We concurrently measured the particle air pollution within the underground subway platform and the pedestrian pathway above floor utilizing three varieties of screens. We took measurements for six hours a day, from about 9 a.m. to three p.m., on 5 weekdays throughout the summer time of 2022.
What’s subsequent
The following step on this mission is to reveal lung cells within the lab to the air air pollution particles from the fifteenth Road Station and measure the oxidative stress attributable to the particles. This stress contributes to continual illnesses, together with bronchial asthma, continual obstructive pulmonary illness and lung cancers.
We may even study the varieties of air particles, and the degrees of assorted metals in them, to find out what about these particles from the subway causes stress to lung cells.
The Analysis Transient is a brief tackle fascinating educational work.