Toxins in your home

Although cooking can produce pollutants such as acrolein and PM 2.5, range hood fans can get rid of them before they spread to other parts of the home. 

FAIRBANKS — The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy and the many other parts of home life. 

Although most people know the dangers of carbon monoxide, secondhand smoke and radon, studies show lesser-known toxins such PM 2.5, acrolein and formaldehyde actually pose a bigger health threat inside your home 

In fact, the tiny particles known as PM 2.5 are the most harmful pollutants in the indoor environment. PM 2.5 is generated from smoking, burning wood, cooking or lighting candles. The particles enter the body through the lungs and can move quickly into the bloodstream, causing respiratory and heart problems especially dangerous for children and the elderly.

Volatile organic compounds are chemicals that can be harmful in a gaseous state. In homes, the most common VOCs are acrolein, produced from cooking, and formaldehyde, which off-gasses from items such as furniture and paint. These gases can cause respiratory irritation and, in the event of long-term exposure, cancer.

Then there are hazards that are easier to spot, such as mold. With the right amount of humidity and a cold condensing surface, mold can find a nice growing environment in your home. In the U.S., roughly 20 percent of respiratory diseases can be attributed to dampness and mold within homes. Fairbanks homes are especially susceptible to moisture issues because the large temperature differences between the indoors and outdoors leads to greater vapor drive in the building envelope.

So how do you know what’s in your home?

While mold is often visible and can give off a musty smell, it can be hard to spot other pollutants that have no clear footprint. Rather than worry about each individual pollutant, think of the air as a whole. If too much moisture is in the air — for example, your windows are collecting water — then pollutants are likely in the air. If the house smells musty, you probably have a variety of pollutants you cannot smell as well.

Addressing poor IAQ

So how do you address these hidden dangers in your home? The best way to alleviate poor IAQ is to exchange stale indoor air with clean outside air. In other words, ventilation.

While every home has some degree of natural ventilation because of air leaking through holes in the building envelope, today’s homes are being built tighter than ever. That means you can’t rely on natural leakage alone to keep your living area healthy.

That leaves mechanical ventilation, or using fans and vents to exchange indoor and outdoor air. Experts recommend one-third to one-half complete air changes per hour. That means every 2-3 hours you’re replacing all the indoor air with fresh outdoor air.

There are several options for this: a bathroom fan, range hood or a heat recovery ventilator. Bathroom and kitchen fans focus on point sources of pollution. Since cooking is a major source of PM 2.5 and acrolein, it makes sense to get rid of them right away before they spread to the rest of the house. Turning on your range hood when cooking is a simple way to keep your air clean. Running your bath fans more often than just after a shower can help exchange more air throughout the house.

The ideal option for a cold climate is a balanced, ducted system that uses a fan like a heat recovery ventilator. A ducted system makes sure air from all parts of the house is exchanged on a regular basis, getting rid of gases such as formaldehyde that may be coming off carpet. HRVs protect your home from pressure imbalances by bringing in the same amount of air as they exhaust — so you don’t have to worry about backdrafting your appliances or sucking in dangerous soil gases. And they lower your heating bills by capturing energy from warm exhaust air and transferring it to fresh cold air.

To read more about our indoor air quality study visit

Ask a Builder articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, contact us at or 457-3454.