Although it may seem counterintuitive, indoor air is typically two to five times more polluted than outdoor air. As energy-efficient homes become tighter and tighter with less air infiltration, indoor air quality deteriorates without proper ventilation and mindfulness. With numerous sources of indoor air pollution found within the home, it’s important to minimize them while boosting healthy practices. Thankfully, there are many simple actions you can do for cleaner air.
1. Use Natural Fragrances
Although you may associate pine, lemon or botanical scents with cleanliness, synthetic fragrances can emit numerous volatile organic compounds (VOCs) that evaporate or off-gas into the air at room temperature. Some of these compounds are known to be toxic or hazardous. One fragrance can contain a couple hundred chemicals. Conventional laundry products, cleaning supplies, air fresheners and personal-care products may contain numerous toxins, although it might merely be listed as “fragrance” on the label.
To reduce your exposure, use mild cleaners that don’t contain fragrances or make your own with essential oils. Avoid using products that have fragrances in the list of ingredients, and be aware that some products labeled unscented even contain fragrance (so read the ingredients list). For healthier personal-care products, refer to the Environmental Working Group's Cosmetics Database, and use baking soda, essential oils or ventilation to remove unwanted odors.
2. Prevent Mold and Moisture
Molds can produce allergens, aggravate asthma symptoms and, in some cases, produce toxic chemicals. They can irritate the skin, eyes, nose, throat and lungs, regardless of whether the person is allergic to mold or not. Wet surfaces can start growing mold in just 24 to 48 hours.
Moisture is the most important factor impacting mold growth. Look for mold growth around leaky plumbing fixtures, around the foundation, and near windows and sinks. Common sources of water include leaks from floods, the roof, plumbing fixtures, humidification systems and sprinklers. Stop the source of moisture entering your home, clean mold where possible, or replace items that cannot be properly cleaned such as carpeting, ceiling tiles or furniture. Avoid breathing in mold when making repairs. For severe water damage, consult an expert.
3. Install a Home-Ventilation System
Some of the super energy-efficient homes of the 1970s were so airtight they developed indoor air quality issues. Stale air and moisture couldn’t exit the home, and fresh air wasn’t coming in. “One thing that a lot of people got wrong when building super tight houses was not ventilating them well,” says Brian Hughes, a carpenter for GO Logic who lives in a virtually airtight home at Belfast Cohousing & Ecovillage with a Zehnder ventilation system.“It might not be intuitive that [airtight] homes need to be ventilated.” Hughes believes that heat recovery ventilation (HRV) and energy recovery ventilation (ERV) systems have revolutionized high-performance homes because they allow a constant stream of fresh air while not compromising energy efficiency.
HRV systems extract stale air from the home and supply preconditioned fresh air from outside. In warm weather, Zehnder HRV systems pre-cool the intake air using the exhaust air, without the two streams mixing. In cold weather, the heat from the exhaust air is transferred to the intake air. These systems are up to 95 percent efficient. ERVs transfer both heat and humidity and ERV systems help maintain comfortable moisture levels within the home.These ventilation systems boost indoor air quality by removing moist air, odors, smoke, and fumes and replacingstale airwith fresh, filtered air.
4. Use Low-Emission Products
Many of the goods we use in our homes release VOCs. Many dry cleaners use a solvent called perchloroethylene (PERC), which can damage the brain and central nervous system and is a likely carcinogen. Formaldehyde is found in numerous home products, including particle board, plywood, paints, adhesives and vehicle exhaust, and is a human carcinogen. “It’s the smell in new houses, and it’s in cosmetics like nail polish,” says Otis Brawley, doctor and chief medical officer at the American Cancer Society. “All a reasonable person can do is manage their exposure and decrease it to as little as possible. It’s everywhere.”
To avoid exposure to PERC, look for cleaning businesses that use CO2 or wet-cleaning methods, alternatives that are safe for most clothes or air out recently dry-cleaned clothes before bringing them into your home. To reduce your exposure to formaldehyde and other VOCs, be mindful of the products that you bring into your home. Unwrap and let new furniture and carpeting off-gas in a garage for a few days before bringing it inside. Use solid wood products, or ensure that pressed wood products are sealed on all sides. Use no- or low-VOC paints and adhesives, and increase ventilation during painting projects. Potentially hazardous products often contain warning labels stating to use the product in a well-ventilated area. Whenever possible, find safer alternatives or use such products outdoors and allow projects to dry before bringing them indoors.
5. Grow Indoor Plants
It’s common knowledge that plants add oxygen to the air, but did you know they also remove numerous toxins, including formaldehyde, benzene (found in glue, paint and auto fumes) and trichloroethylene (found in paint stripper and spot remover)? A study by the University of Technology in Sydney, Australia, found that indoor plants reduce anger by 44 percent, depression by 58 percent, fatigue by 38 percent and anxiety by 37 percent.
Most common houseplants have been shown to boost indoor air quality. Aloe vera clears benzene and formaldehyde; spider plants remove smog, formaldehyde, benzene and xylene; and snake plants clean smog, formaldehyde and trichloroethylene from the air. Aloe vera and snake plants are also ideal for the bedroom because they release oxygen at night.
Sarah Lozanova is an environmental and health journalist with an MBA in sustainable management. She lives in a net-zero house in Belfast Cohousing & Ecovillage in midcoast Maine with her husband and two children.