Fall and Winter Create Specific Sources of Indoor Air Pollution

Fall and Winter Create Specific Sources of Indoor Air Pollution

Indoor air pollution can be an issue at any time of the year, but colder months tend to bring their own season-specific contaminants to indoor environments. While regional differences certainly should be taken into account (winter in Los Angeles means something entirely different from a winter in Buffalo, NY or Charleston, SC, for example) it’s still worth noting that dramatic shifts in temperature can call for adjustments from most homeowners.

In most climates, cooler weather tends to drive people indoors more often and for longer periods of times. Add to this that modern housing has become more efficient (read: more tightly sealed and insulated), so fumes, debris and pollutants are less likely to escape a home once they’re introduced into the air. Because of these conditions, it can be argued that a person’s exposure to indoor air pollutants can significantly increase in the fall and winter.

Sources of indoor pollution that tend to be greater in colder months:

Combustion and smoke

Many people turn to additional sources of heat when the temps drop: fireplaces, wood-burning stoves, portable heaters. Many of these rely on gas, oil, wood, coal or kerosene for power…which, when burned, can produce potentially harmful fumes, chemicals, odors and soot. All of those are pollutants that can worsen or trigger allergy and asthma attacks in those with vulnerable respiratory or immune function. Smoke from wood-burning stoves (or someone burning leaves outside) can also aggravate breathing.

Mold & mildew

Piles of damp leaves, puddles of melted snow or ice, and unseasonably wet spells can mean an abundance of mold and mildew within a home. Even in a particularly dry winter season, pipes can freeze and burst, leaving pockets of unwanted moisture in walls and flooring. Mold and mildew allergies are quite common, and can mean an unpleasant experience for many sufferers. Breathing in mold spores, which can become airborne and are easily inhaled, is especially damaging.


Whether it’s a big, beautiful fir tree in your living room all December or cookie-scented candles, natural and artificial sources of fragrance in your home can add to indoor air pollution levels. The scent of freshly-clipped greenery is pleasant to some and irritating to others; if you’re sensitive or asthmatic, their presence can create an issue. Artificial fragrance in candles, potpourri or simmering liquid can be a bit more dicey: depending on the chemical makeup of the fragrance (which can be difficult, if not impossible, to pinpoint) scented items can release VOCs (volatile organic compounds), headache-inducing fumes or sickly-sweet smells that can be irritants to those with breathing issues.


In addition to the artificial fragrances they may contain, candles can contain questionable chemicals and produce soot, a very small particle that can be easily inhaled. Over time, soot can discolor walls and furniture, and gunk up a home’s ventilation system.

Carbon monoxide and nitrogen dioxide 

Carbon monoxide (CO) is an odorless, colorless gas, and in abundance, can be deadly. It forms when there’s not enough oxygen to produce carbon dioxide, such as when operating a stove or an internal combustion engine in an enclosed space.

Nitrogen (NO2) dioxide forms when fossil fuels such as coal, oil, gas or diesel are burned at high temperatures.

Once you’re aware of the things that can be polluting the air in your indoor environment, you can take steps to reduce or eliminate those factors.

  • The best way to control combustion pollutants is to make sure combustion appliances are installed and maintained by reliable professionals, and properly used. A UL-listed CO monitor should also be installed.
  • Repair leaks immediately and make every effort to thoroughly dry any affected furnishings or building materials that have gotten wet.
  • Use natural scents (like simmering a mixture of water, cloves, cinnamon and vanilla extract) to fragrance your home instead of artificial scents.
  • If you burn candles, use beeswax or soy instead of paraffin.
  • Using a high-grade air purifier can help reduce or eliminate dust, dust mites, dander, contaminants and airborne pollutants from your indoor space.
  • Regular vacuuming can also help lift dirt, dust and allergens from surfaces in your home. Choose a vacuum with a sealed HEPA filter, which will help prevent these contaminants from being blown back out into the air.


Leave a Reply

Your email address will not be published. Required fields are marked *