The Air Indoors
It has been heartening, in the four months since I have been working on this series, to see the interest everyday citizens are now taking in Salt Lake’s air quality. At parties, book group meetings, dinner with friends, yoga classes, on ski lift rides…the conversation often turns to air quality.
I hear complaints about our public transport system, government officials, and polluting refineries; I hear ideas, both fantastical and practical, for cleaning up the air; and I hear questions—often the same questions—posed over and over. So I’ve decided, in this column, to address the questions I hear most often.
I’m worried about my health. What made you decide to see a doctor?
The kicker for me was, while at rest, I could bring in a big breath of air—my nose and lungs felt clear—but my body did not feel oxygenated. I now know that PM2.5 particles lodge deep in the alveoli of the lungs. The alveoli are responsible for transporting oxygen from the lungs to the bloodstream (and thus the rest of the body); when they are blocked with pollutants, they can’t do that job efficiently. Once PM2.5 is in the alveoli, it is there to stay.
That’s why it’s so important not to exercise outside in poor air even if you have no symptoms. (For more details on the health effects of bad air, see “What Causes Salt Lake’s Air Pollution, and Why You Should Care,” November CATALYST.)
OK, so I’m staying inside. But is the air inside my home any better than the outside air?
When we suffer through a red air day, some amount of particulate pollution infiltrates your home. How much depends upon how well sealed your doors and windows are and how often you enter and leave the house. In a poorly sealed home, full air exchange from the outdoors can take place in a matter of hours. Today’s homes tend to be well-sealed, keeping the bad outside air out and improving home heating efficiency.
But the dark side of a well-sealed home is that it keeps indoor pollutants in. In fact, indoor air pollution is sometimes five to 10 times higher than outdoor air pollution and can be up to 100 times higher, even during a green air day—depending in large part on your lifestyle choices and, perhaps, geology.
Bad indoor air comes from four main sources: volatile organic compounds (VOCs), carbon monoxide (CO), particulate pollution, and radon.
VOCs stem from chemicals people store and use in their household (cleansers, air fresheners, scented candles, hairspray, incense, etc.) and from the chemicals used in construction products and furniture (wall paint, sealants, formaldehyde in cabinetry, chemicals in stain-resistant fabrics and carpets, wood stains, chemicals added to mattresses). Reduce your risk by storing chemicals in a detached garage or shed and using environmentally friendly cleaners, low-VOC paints, water-based low-VOC wood finishes, and chemical-free personal hygiene/ cosmetic products.
Indoor particulate pollution originates from cooking and baking, decomposing hair and skin flakes, molds and mildews, wood fires (these also create toxic carbon monoxide), burning candles, car exhaust from attached garages, and tobacco smoke.
Keeping a clean, mold- and smoke-free home is your first line of defense. A HEPA vacuum cleaner does the best job of keeping your carpets clean without stirring up the dust particles; wet mopping is the best choice for floors (except cork!). When you cook or bake, turn on your range hood fan to ventilate fumes to the outdoors. If your range hood merely recirculates the air, consider having a professional modify it with the necessary ductwork to ventilate to the outside.
Radon is an odorless, invisible toxic gas found in the ground throughout the Salt Lake Valley; it is the leading cause of lung cancer among non-smokers in the US. Although radon is not a problem outdoors, inside the home it can build to high concentrations, as well as attach to dust particles. When you breathe the dust in, the particles lodge inside your lungs just as PM2.5 does.
Radon levels vary widely throughout the Valley, including from house to house on the same street (and even room to room within a house), so it’s wise to test your house even if your neighbor’s level is low. Radon test kits are cheap and readily available at Home Depot and other stores.
If your home tests high for radon, you can look into having the problem professionally mitigated. The state of Utah provides a list of certified radon mitigators (radon.utah.gov).
Running the blower on your furnace 24/7 will continually drive your indoor air through your furnace filter, reducing all types of indoor pollution, including effects from radon (radon is most dangerous when it attaches to dust particles that are then inhaled, since these lodge in the alveoli). A good MERV 16 filter (minimum efficiency reporting value) that fits into your furnace is the most effective way to clean your air of dust and allergens; it will capture 95% of the microscopic PM2.5 that is so worrisome. Common upscale filters available at hardware stores range from MERV 11-13; these filters capture 70-90% of PM2.5 in your home. Make sure you follow the manufacturer’s recommendations for cleaning and/or replacing the filter, or it will clog with particulates and not function properly. For maximum benefit, keep your furnace and ductwork clean and in good repair as well.
You can up the ante by adding an in-line or free-standing air purifier to your indoor arsenal. Choose a HEPA air filter; these filters remove 100% of sub-micron particles and pretty much everything larger. Manufacturers claim a free-standing HEPA purifier thoroughly scrubs the air in up to a 1,500-square-foot area every 15 minutes.
What about my child’s school, my work place, or the gym/yoga studio where I work out? Is anyone regulating the indoor air in these types of spaces?
Gregg Smith, Director of Facility Services for the Salt Lake City School District, says Utah public spaces are expected to maintain indoor air quality standards set by various building codes, which require buildings to bring in 15 cubic feet per minute per person of outside air. Smith says the district’s schools adhere to this standard.
But when the outside air has heavy concentrations of PM2.5 or other pollutants, that’s like inviting the cat in with the canary.
Randy Martin, an Environmental Engineering professor at Utah State University, studied the indoor air at schools in the Cache Valley and in several buildings on the USU campus, and found the air had about 25% of the PM2.5 concentration of the outdoor air on cold inversion days. This figure matched that found in a study conducted by the University of Utah at Hawthorne Elementary School. A Department of Air Quality monitoring system is permanently installed outdoors there, and a similar monitoring system was installed inside the school. The indoor monitor registered a 75% decline in PM2.5 compared to the outdoor monitor. This means that on a red air-quality day, when the Air Quality Index (AQI) is 200, for example, the indoor AQI would be 50, on the border of green/yellow.
Not bad, till one considers that, at least in part, it’s the children themselves who are scrubbing the air, as they trap many of those PM2.5s in the alvioli of their young lungs. [RUN BY MM]
“There is a massive void in regulation of indoor air,” says Dale Keller, Salt Lake County’s Environmental Health Bureau Manager. “This is a huge problem, because people stay inside during bad air episodes, hoping to get some relief. But are they?”
Keller and co-worker Victor Alaves, Environmental Monitoring and Industrial Hygiene Program Administrator, point out that buildings where people congregate, such as movie theaters, fitness gyms, yoga studios, churches, and nursing homes should meet International Building Code standards when initially constructed, but there is no follow-up once the building is in use. In addition, buildings that are converted to a different use (spa to yoga studio; boutique to nail salon, for example) may not engage a building inspector during the remodel and therefore may not meet code for the new use. “Only tobacco smoke is regulated by the County Health Department,” says Alaves. “I am not aware of any agency that regulates or inspects public buildings after construction.”
Most public buildings have HVAC (heating and air conditioning) systems with MERV (minimum efficiency reporting value) 7 or 8 filtration systems. A MERV-8 system is capable of filtering out such items as mold, spores, dust-mite debris, cat and dog dander and hair spray. You would have to go to at least MERV 12 (out of a possible 16) to get PM2.5 out of the indoor air.
But perhaps your fitness gym, yoga studio, or school has taken it upon themselves to beef up its system. A spot check of buildings around town found that Rowland Hall school installs MERV 10 filters during winter and summer bad air months (they otherwise use MERV 7 filters), and Centered City Yoga in the 9th and 9th area has top-rated HEPA purifiers on each floor of its studio. Kudos to these and any other facilities that have gone the extra mile even though no one is forcing them to. Not sure how your workout place or school fares in this regard? Ask.
OSHA regulates certain indoor air pollutants (but not PM2) in work spaces; more important, it requires that nothing may exist that is hazardous to one’s health. But OSHA focuses on hazards such as unstable ladders and slippery floors, and is unlikely to respond to a complaint about indoor air quality.
If your work building has leaky seams and you experience burning eyes and throat on orange or red air days, ask your human resources department about upping the MERV rating on its filtration system. If you run into a wall and work in an enclosed office, you can always buy your own freestanding HEPA purifier.
Finally, Salt Lake County Health Department’s Keller and Alaves say they are working on standards for acceptable levels of pollutants in indoor air, and that these guidelines should be ready by the end of this year. “There’s nowhere to go, for people who want this information,” says Keller. “We will be providing not only recommendations for safe levels of indoor pollutants, but also information on how to attain those levels.”
However, the County Health Department can only advise and educate. Regulations themselves must come from the Utah County Board of Health or the Legislature.
Should I be wearing a mask or respirator when I am walking outside on a bad air day?
Light masks, such as surgical masks, filter out about 70% of PM2.5; way better than nothing. Heavy duty respirators can filter more completely but are cumbersome, can fog up glasses, and are difficult to breathe through if you are riding a bike, power walking or doing other aerobic activity.
That said, a Facebook query on the topic yielded the following recommendations for high-quality, non-fogging filters:
• 3M’s 6391 Reusable Respirator Gas Mask, with P100 filters, and their R-2091 Particulate Filter, with P100 filters. Both can be purchased on Amazon for from $12 to $25 (used or new).
• If you want something lighter and less alien-looking, check out 3M’s N95 8511 Particulate Respirator Mask, which the company claims filters 90% of PM2.5. (Its 8210 model is sized for children.) It does not contain filters, though, so you’ll need to replace the mask often—once a week if you are wearing it daily in red air conditions.
What are other polluted cities doing?
Mexico City has geography similar to Salt Lake City—a valley surrounded by mountains. In 1990 Mexico City was named the most polluted city in the world by the United Nations. It was considered the most dangerous city for children to grow up in until residents and politicians decided geography was no longer an excuse for breathing toxic air.
A number of programs were initiated, but the real game changers came when government initiated a “No driving today” program—cars with license plates ending in certain numbers were banned from the roads on specific days—and the largest oil refinery in the country, which was located in central Mexico City, was shut down.
In announcing the shutdown, President Carlos Salinas de Gortari said, “The government is prepared to impose upon itself the most severe measures to protect public health and to respond to social demands. Let’s plant trees where today there is nothing but pipelines.” The refinery was replaced with public parks and green space. The result: By 2012, PM2.5 had dropped 70% and ozone 75%.
“Road rationing,” as restricting the number of vehicles on the road is called, is also in place in Santiago, Chile; Sao Paulo, Brazil; Bogota, Quito, and La Paz, Bolivia; and in some areas in Costa Rica. It’s an extreme idea in the car-crazy US, but extreme conditions sometimes require extreme actions.
So air quality is yet another criterion in choosing a gym or a yoga studio. And what about your church? As an individual, you have the power to choose.
As we increase our understanding of the causes, dangers and control methods of polluted air, let’s remember what Smoky the Bear said: Only You Can Prevent Forest Fires.
You can make your concerns about industry and public transportation known to your elected officials (the Legislature is now in session!). You can ask for tougher restrictions on wood burning and for restrictions on driving. And you can take it upon yourself to drive less and more thoughtfully. Together, we can make this happen.