If You Care, Spare the Air
Maintaining reasonably clean air is not merely an environmental issue but a public health issue.
Air pollution has tremendous impacts on human respiratory and cardiovascular health, not to mention the ecosystem. The Bay Area has made great progress towards reducing air pollution, but over 3 million residents are part of one or more “sensitive groups” which are particularly adversely impacted by poor air quality: asthmatics, children, the elderly, people with cardiovascular disease or diabetes, and people in poverty.
To find out whether you should take any precautionary actions based on the outdoor air quality, you can check the Air Quality Index (AQI) for your area here. Developed by the EPA, the AQI converts measured concentrations of each air pollutant to an “index” based on the corresponding “level” of health concern warranted. AQI values between 0–50 are considered “good,” values between 101–150 are “unhealthy for sensitive groups,” and values over 300 are “hazardous.” Here are general guidelines and cautionary statements for each level:
How can we address air quality issues?
To address air quality issues, it is helpful to first recognize a few of the most common pollutants and their sources. Nitrogen oxides (NOx), mostly produced by industrial waste and motor vehicle exhaust, are largely responsible for the brown haze seen on “smoggy” days in the Bay Area. Sulfur dioxide, a similar pollutant, is less prominent here than elsewhere. Volatile organic compounds (VOCs), often contained in industrial solvents, petroleum refining, and consumer products such as paints and aerosol sprays, are of serious concern in the Bay. Carbon monoxide, one of the deadliest air pollutants, is of relatively low concern in the Bay Area currently, and the primary sources of it are cars and seasonal wood burning.
Ozone pollution can be particularly bad in some parts of the Bay during the summer, because sunlight catalyzes the reactions that produce ground-level ozone from precursors such as NOx, carbon monoxide, and VOCs. Wood smoke pollution is also a serious concern in the area, especially when there are wildfires, or during the winter months when wood burning is used for heat. Fine particulate matter is categorized according to its average particle diameter in microns. As a general rule, the finer the particle, the more hazardous it is to health, because finer particles both take longer to settle out of the air, and penetrate more deeply into the lungs when inhaled. PM10 particles are under 10 microns, PM2.5 are under 2.5 microns, and PM1 microns are under 1 micron in diameter. In the Bay Area, only PM10 and PM2.5 concentrations are regularly reported.
Over the past few decades, California has made tremendous strides to improve the health of the air its residents breathe. Nevertheless, 7 California metropolitan areas, including San Jose-San Francisco-Oakland, rank in the top 7 most polluted U.S. cities according to the American Lung Association. Programs implemented to address this include the California Airborne Toxic Control Measures, which set limitations on emissions and performance for various activities that contribute to air pollution. The Bay Area Air Quality Management District manages the Spare the Air program, which alerts residents of air quality conditions, and prohibits wood burning when particulate matter levels are forecast to be high.
What can you do personally to protect yourself from polluted air?
One way to reduce the impact of air pollution on your health is to ensure that you have an airtight seal on your home, and keep your doors and windows closed on unhealthy air days. This will help “reduce in-home exposures to fine particles from outdoor sources such as vehicle exhaust”. Proper ventilation is crucial to reduce household air pollution, especially if your home was built in the 1970s or earlier and contains asbestos or lead. If your home is not well-sealed and does not have a good built-in filtration system, the Department recommends “1) add enhanced filtration to the forced air heating system or 2) use a standalone air filtration unit with a high efficiency filter.” Filters designed for use with whole-house ventilation systems in homes are given a MERV rating on a scale of 1 to 16, in which higher numbers correlate with greater efficiency in removing fine particles from the air. LEED recommendshaving a filter rated MERV-8 or higher, while the US Department of Energy recommends a MERV-13 filter. It’s essential to have a home carbon monoxide detector, but you may also want to purchase a home air quality monitor to measure PM2.5, VOCs, formaldehyde, and humidity (to predict the presence of mold).
Finally, the EPA and the U.S. Forest Service have outlined some recommended actions that you can take to help reduce your contribution to air pollution. These include: carpooling, limiting daytime driving, refueling only after dusk, taking public or manual transportation when feasible, keeping your car and/or boat engines properly tuned, and setting your air conditioner to the highest comfortable level (unless your health requires otherwise). When particulate levels are a concern, avoid burning wood and using gas-powered lawn and garden equipment. In short, if you care, “Spare the Air.”
At SAMI-Aid, we believe in promoting a healthier world and helping people like you live a healthier lifestyle.