A few years ago, an MIT professor entertained students with a mind-boggling notion: With every breath they took, it was statistically nearly certain that one molecule of that air had been exhaled by Julius Caesar as he took his final breath more than two thousand years ago. Because people breathe in and out more than 20,000 times a day, it may be worth considering what else, besides Caesar’s last gulp, is in that air. Outdoors, pollutants are rapidly dispersed. Indoors, contaminants can become much more concentrated. The EPA estimates people now spend about 90 percent of their time indoors, potentially exposed for long periods to those contaminants.
Safe to say, Caesar didn’t have to worry about most of the things that now concern homeowners looking to improve the quality of their indoor air. And every room brings its own concerns. Some chemicals do stand out, though.
“First thing I’d do is keep urea formaldehyde out,” says Alli Kingfisher, Green Building and Sustainability Specialist with the Washington State Department of Ecology. Urea formaldehyde is used in building materials such as pressed-wood particle board and is found in everything from furniture to kitchen cabinets to subflooring.
In addition to its unpleasant odor, formaldehyde is implicated in triggering asthma attacks and is also known to cause cancer in animals and humans. Formaldehyde levels generally decrease as a home ages, provided new sources aren’t constantly being added. Concerned homeowners can use air conditioning and heating to maintain a moderate temperature and lower humidity to slow release of formaldehyde. Avoid urea formaldehyde in the first place by asking suppliers for exterior-grade plywood and urea formaldehyde-free insulation, shelving, window and door trim, and base moldings if you are remodeling.
Next up on the list of indoor air quality culprits are volatile organic compounds, or VOCs. VOCs are found in literally thousands of objects and materials often in homes, including paints, cleaning supplies, building materials and furniture, and even craft materials, copiers, printers and permanent markers. Concentrations of VOCs are often 10 times higher indoors than out, and they can persist in the air for a long time. Some VOCs can damage the liver, kidney and nervous system. Some cause cancer. One sniff can tell you what the EPA confirms — levels can skyrocket during use of such volatile chemicals as paint strippers, exposing users to up to 1,000 times greater levels than the “background” outdoor level.
To minimize exposure, “You always use water-base finishes, or no-VOC finishes or at least low-VOC, for paint, cabinets and floor finishes,” says Kelly Lerner, Spokane architect and owner of One World Design, as well as the author of Natural Remodeling for the Not-So-Green House.
“Greenseal standards is a good label you can trust,” when searching for low VOC products adds Kingfisher.
Kingfisher says the third class of unhealthy airborne chemicals are PBDEs — polybrominated diphenylethers. Introduced to reduce fatalities from fires by slowing burning, PBDEs are found in everything from appliances and electronics to the foam used in furniture and carpet padding. They’re also now turning up in strange places — like human breast milk, fish and aquatic birds, and in air, soil and water. Health effects in humans haven’t been studied extensively, but in animals the chemicals caused problems with reproduction, brain development and behavior.
Banned in Europe, some forms of PBDE are also banned in at least some states (including Washington) or will be soon, but that just means new sources should be declining. What about stuff already in your house?
A common route of exposure is through dust, so using damp cloths to dust furniture weekly and vacuuming using a HEPA filter and plenty of ventilation can help. According to the Environmental Working Group, foam items manufactured before 2005 most likely contain PBDEs. It’s when the foam breaks down and becomes part of regular household dust that it can cause problems, so replace items with deteriorating foam. Be aware that foam carpet padding may contain PBDEs, so use care when replacing it — and clean up afterward with a HEPA filter vacuum. Notably, Apple, Microsoft, LG Electronics, Phillips, Samsung, Sharp, Sony-Ericsson and Toshiba are among companies that have pledged to eliminate all PBDEs from their products.
It would seem that constant air circulation from the outdoors would make for better quality indoor air. Not so fast, says Oscar Torres, architect and owner of Design Services Northwest. Although building codes require a certain number of air exchanges in homes each day, drawing in outdoor air can wreak havoc on occupants suffering from seasonal allergies.
“The air movement is a double-edged sword,” he says. “If the person is allergic, they just have to suffer through it.”
To minimize blowing dust around the home, Torres recommends radiant floor heat, if that fits the budget. But there are ways to improve indoor air even if you have a furnace or air conditioner.
“Change your filters at least once a month in Spokane County,” Torres recommends. He notes that filters to fit inside floor vents are also available to snag pollen and dust before it enters your home.
Good design can also help minimize the use of heating and air conditioning. Deciduous trees can offer summer shade, while allowing winter sunshine to warm a home. “If you’re willing to manage curtains and window coverings, that can do quite a bit,” Torres says, to reduce reliance on heating and cooling.
Those hidden sources of indoor air pollution are important, but Lerner says people can be too complacent about stuff that comes into their homes quite purposefully. “You look under most people’s kitchen sinks and they have a whole host of toxic things under there.”
Kingfisher concurs: “I think there’s a lot of assumption that if you go to a hardware store and you can buy it, it’s not that bad for you, because if it was really bad, you couldn’t sell it.” Kingfisher says consumers need to pay close attention to warning labels on products. Storing products in the kitchen is also not recommended.
Because of high levels of naturally occurring radon here, Lerner always recommends clients do a radon test to make sure indoor levels are in the safe range. Torres agrees: “Radon mitigation is a factor in this area,” but, he cautions, “The science behind it isn’t 100 percent yet.” Perforated piping installed under the foundation slab can direct the naturally rising gas skyward. In cases where levels are higher, fans can be added to pull radon safely up and out of the home.
To learn more about PBDE, go to www.oregon.gov/DHS/ph/envtox/docs/pbdefactsheet.pdf. For information on VOCs and urea formaldehyde, go to www.epa.gov/iaq. For more on environmentally friendly residential building practices, go to www.certifiedbuiltgreen.org. Also, the American Lung Association offers free home inspections by Master Home Environmentalists to identify problems and develop a plan. Call (509) 325-6516.
Safe Stone
One part of the house that many people don’t expect to have an effect on indoor air quality is their kitchen counters. Especially the beautiful, shiny, granite ones that are so desirable realtors often recommend them to help sell a home. But those luxurious counters may be a source of radiation. “The only way that you can really know with granite is to do a little radon test,” available at area hardware stores for about $15, says Spokane architect Kelly Lerner. “If you are really in love with granite… it needs to be in an enclosed area [during the test], you do the little test and send it off to the lab. You don’t want to put in a kitchen counter that is going to give you lung cancer.”
