Tracking indoor air quality can help mitigate home pollution

Washington: Tracking the indoor air quality in real time can encourage people to change their behaviour and switch to activities that cause less pollution within their homes, a study has found.

Researchers from University of Utah in the US conducted a study to determine if homeowners change the way they live if they could visualise the microscopic air pollutants in their homes.

"The idea behind this study was to help people understand something about this invisible air quality in their home," said Jason Wiese, an assistant professor at University of Utah.

Researchers built a series of portable air quality monitors with Wi-Fi and connected them to a server. Three sensors were placed in each of six homes from four to 11 months in 2017 and 2018. Two were placed in different, high-traffic areas of the house such as the kitchen or a bedroom and one outside on or near the porch.

Each minute, each sensor automatically measured the air for PM 2.5 -- a measurement of tiny particles or droplets in the air that are 2.5 microns or less in width -- and sent the data to the server.

The data could then be viewed by the homeowner on a tablet that displayed the air pollution measurements in each room as a line graph over a 24-hour period. Participants in the study could see up to 30 days of air pollution data.

To help identify when there might be spikes in the air pollution, homeowners were given a voice-activated speaker so they could tell the server to label a particular moment in time when the air quality was being measured, such as when a person was cooking or vacuuming.

Participants also were sent an SMS text message warning them whenever the indoor air quality changed rapidly. One homeowner discovered that the air pollution in her home spiked when she cooked with olive oil.

That motivated her to find other oils that produced less smoke at the same cooking temperature, researchers said. Another homeowner would vacuum and clean the house just before a friend with allergies dropped by to try and clean the air of dust.

However, she found that this made the air much worse because more pollutants were kicked up when vacuuming and dusting.

Realising this, she started cleaning the house much earlier before the friend would visit.

Participants would open windows more when the air was bad or compare measurements between rooms and avoid those rooms more with more pollution.

"Without this kind of system, you have no idea about how bad the air is in your home," Wiese said.

"There are a whole range of things you can't see and can't detect. That means you have to collect the data with the sensor and show it to the individual in an accessible, useful way," he said.