Boston’s Chinatown has some of the most toxic air in the city, as tens of thousands of cars produce exhaust driving down the I-93 Expressway and Mass Turnpike. The clear blue skies create the illusion that air pollution is not a problem here. However, the dirty air from cars invisibly harms Chinatown residents’ health.
Cars burn gasoline, producing exhaust fumes. “Car exhaust contains nitric oxides (NOx), which gets converted in sunlight to ozone: ozone on the ground level is very toxic to humans, while ozone in the outer atmosphere is good for humans,” said Brian Helmuth, joint professor of College of Science and School of Public Policy and Urban Affairs in Northeastern University.
Ultrafine particles are produced by vehicular emissions and found in the highest concentrations on expressways. The particles are far smaller than the regulated PM10 and PM2.5 particles, even finer than a strand of hair. They are considered respirable particles due to how small they are, making them easier to inhale. Ultrafine particles have more aggressive health implications than larger particulates, harming the heart along with the lungs.
“Both ozone and particulates can severely trigger asthma attacks, and living by major highways and busy streets does elevate the risk [of getting or exacerbating asthma],” said Helmuth. For example, children have higher metabolic rates and use much more oxygen than adults. In other words, children breathe more pollution in and are affected by it more severely.
UCLA researchers found exposure to air containing ultrafine particles for a few hours a day over five days significantly increased allergic airway inflammation, which correlated to changes found in the immune system and expressed genes. Recently, Helmholtz Association researchers found allergic people are likely to react more strongly to ultrafine particles than non-allergic people.
Asthma, which affects 15 to 20 million people in the United States, is a chronic inflammatory disease of the small airways in the lungs and can trigger acute episodes of airway tightening and wheezing. Residents living near highways can take steps to mitigate air pollution and prevent asthma attacks:
- Close your windows: Keep windows and doors closed during peak traffic times, such as morning and evening rush hours, as well as winters, when pollution is the most severe. If you do need to open the windows, try to keep windows by the highway closed.
- Filtration: Studies have shown that filtration in schools can improve indoor air quality by reducing particle concentrations by as much as 97 percent relative to outdoor levels. Tenants can speak to landlords about effective filtration for their homes.
- Mechanical ventilation: In mechanical ventilation systems, air is circulated through a building by air intake and/or exhaust fans; as a result, the air is always circulating without actually opening the windows. If your buildings have mechanical ventilation, try to use it as much as possible.
- Plants: Plants recycle carbon dioxide into oxygen, for fresher air. They do not block particulates, but are one way to improve home air quality.
This post is also available in: Chinese