Indoor Air vs. Outdoor: Experts Reveal Simple Swaps for Cleaner Home Air

A recent study has shown that you might encounter hazardous amounts of indoor air pollution within your home, regardless of favorable outdoor air quality conditions.

Scientists from the University of Birmingham in the UK monitored particulate matter (PM) contamination in three households for two weeks. Their findings indicated that pollution levels within each residence were both greater and less consistent compared to outdoor measurements. In one household, the WHO’s guidelines for PM2.5 were surpassed on nine out of the fourteen days observed.

Our research highlights the importance of monitoring indoor conditions.

air pollution

“Even if the outdoor air quality is good, individuals may still experience poor air quality indoors,” explains co-author and Clean Air Fellow Catrin Rathbone.

Particulate matter levels showed considerable variation among different households, suggesting that relying solely on measurements from a single site is inadequate.

What leads to elevated levels of indoor air contamination?

Grasping what contributes to indoor air pollution is essential for minimizing your exposure to it.

“Given the increased amount of time people spend working from home, it has become crucial to understand the elements influencing indoor air quality,” stresses co-author and Clean Air Fellow Owain Rose.

The techniques we employed effectively simulated indoor PM concentrations, enhancing exposure assessments with minimal expense.

The researchers pinpointed multiple factors contributing to particulate pollution levels in both indoor and outdoor environments. Inside homes, more foot traffic led to elevated concentrations of larger PM10 particles—those with diameters up to 10 micrometers. Actions such as cooking, smoking, and

heating

Major sources of PM2.5 include tiny particles with diameters of 2.5 micrometers or less.

Structures aren’t capable of filtering outdoor air; thus, particles and pollutants enter via open windows, doors, and cracks in the building envelope. For instance, a ventilation duct from an adjacent eatery significantly influenced pollutant levels within one residence.

How can you reduce indoor air contamination?

While we cannot escape staying at home, there are several actions you can take to reduce indoor air pollution. These steps might appear obvious, yet they have the potential to greatly decrease your exposure to harmful contaminants.

Regularly vacuum your carpets and area rugs.

Using a high-quality vacuum cleaner is an effective method for eliminating pollutants trapped within your carpets and upholstery. This ensures that the majority of particles are suctioned away without being released back into the atmosphere through leaks in the device.

If you’re determined to reduce the amount of pollutants inside your home or deal with allergies, wooden floors are significantly simpler to maintain. Additionally, removing footwear before entering, frequently laundering bed linens, and airing out unwashable items outdoors can contribute to keeping your living space clear of these contaminants.

Open your windows — however, choose wisely

If the air outdoors is cleaner, opening your windows might be an easy way to reduce pollutant particles inside. However, since external factors can also boost indoor contamination, approach this strategy wisely.

If you live near

a busy road

, avoid opening windows during rush hour periods, for instance. According to the Building Engineering Services Association (BESA), it’s advisable to check your area’s air quality index regularly. Keep windows open for extended durations on days with low pollution levels and reduce window-opening time when pollution levels spike.

For instance, participants from a household within the study who experienced reduced overall indoor air contamination tended to prop open a bedroom window during daylight hours.

Replace your gas stove

Each of the three houses in the study featured gas-powered central heating along with a gas-stoked cooktop and oven. Choosing an electric stove might help reduce indoor air contamination.

Gas stoves release various harmful pollutants besides particulate matter (PM), such as nitrogen dioxide (NO₂). In a recent study, researchers from the University Jaume I’s School of Health Sciences in Spain calculated their contribution to this issue last year.

approximately 40,000 premature European deaths annually


.

Earlier research has shown that switching to an electric stove might reduce typical daily indoor NO2 pollution by 56 percent.

The European Public Health Alliance has encouraged EU policymakers to gradually eliminate gas stoves via emission restrictions. However, removing these appliances can come at a significant cost; thus, the EPHA has simultaneously advocated for the implementation of financial inducements to facilitate the transition to more environmentally friendly alternatives.

Use your extractor fan

Operating a range hood and an exhaust fan can assist in eliminating grease, smoke, odors, and humidity remaining in the air post-cooking. Activate these appliances during your cooking process and keep them running afterward to purify the atmosphere.

In the University of Birmingham study, one of the three monitored residences that showed lower pollution levels consistently utilized an exhaust fan during cooking activities.