Indoor Air Pollution

by Collin Dunn, Corvallis, OR, USA on 10.11.07

Science & Technology (science)

Pollution from power plants, cars, and other transportation is a well-known contributor to outdoor air pollution, but indoor air pollution is often worse; it can be up to 10 times worse for you than the air outside. Microbial pollutants like mold, pet dander and plant pollen can combine with chemicals like radon and volatile organic compounds (VOCs) to create a pretty toxic environment in your home; since we spend an average of 90% of our time indoors and 65% of our time inside our homes, according to the National Safety Council that can add up to allergies, asthma and worse.

Everything that comes in to our homes has the potential to be harmful to our health; this includes things from the building materials and elements that hold our homes together to the furniture we sit on and the paint that goes on the walls. Indoor air pollution can be bad, but it doesn't have to be.

Indoor air pollution can be easy to manage once you understand where it comes from. Looking at the image above gives you some idea of the more common sources for poor indoor air quality. In many cases, it comes from chemicals that are part of the things that you bring into your home; the polyurethane common in mattresses, formaldehyde and organic chemicals like dioxin, polychlorinated biphenyl (PCB) and polybrominated biphenyl (PBB) used in lots of furniture and other interior elements are all harmful to us humans. Drapes, carpets and other absorbent fabrics can help trap these nasties, along with dust, mites and other allergens, and our modern, mostly airtight homes keep them inside. Remember this: if there are chemicals and VOCs in a product, there are chemicals and VOCs that could come out, and they won't be good for you if they do.

Not having proper ventilation can also help promote mold and other microbial growth, especially in damp climates; if cellulosic materials (like paper, wood and drywall) become moist and fail to dry within 48 hours, mold colonies can propagate and release allergenic spores into the air. As such, a basic way of maintaining the health of indoor air is by the frequency of effective replacement of the indoor air with cleaner outdoor air.

Aside from keeping known pollutants out of our homes, there are several strategies for keeping the indoor air healthy. At the top of the list is maintaining proper ventilation, which can be done most easily by just opening up the windows at regular intervals (even in the winter). Using green cleaning products can help cut way back on the toxins in your home, as citrus and pine-based solvents can react with ozone to create formaldehyde. Keeping pesticides out of your garden and off your lawn can also help, as they're easy to track in on shoes and clothing. It's also important to keep filters and vents clean, as pollutants can cycle through air ducts and central heating and cooling mechanisms.

For further reading in TreeHugger, check out our top 5 plants for improving indoor air quality, our picks for improving the quality of the air in your homes, and read up on considerations when picking out an indoor air filter. For outside sources, we recommend checking out the US EPA's indoor air quality site, along with the US National Library of Medicine's Environmental Health and Toxicology indoor air quality section and the Medline Plus Indoor Air Pollution section.