Air pollutants inside a home may change your behaviour

Identifying nasty microscopic air pollutants in your home can be a difficult task, but what if you could?

Researchers from the University of Utah conducted a study to determine if homeowners change the way they live if they could visualize the air quality in their house. It turns out, their behaviour changes a lot.

"The idea behind this study was to help people understand something about this invisible air quality in their home," said Jason Wiese, lead author of the study.

During the day, the air pollution inside your home can be worse than outside due to activities such as vacuuming, cooking, dusting or running the clothes dryer. The results can cause health problems, especially for the young and elderly with asthma.

The researchers built a series of portable air quality monitors with Wi-Fi and connected them to a university server. Three sensors were placed in each of six homes in Salt Lake and Utah counties from four to 11 months. 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 and identify 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 home 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.

During the study, researchers discovered some interesting trends from their system of sensors, which they called MAAV (Measure Air quality, Annotate data streams, and Visualize real-time PM2.5 levels).

One homeowner discovered that the air pollution in her home spiked when she cooked with olive oil. So, that motivated her to find other oils that produced less smoke at the same cooking temperature.

Another homeowner would vacuum and clean the house just before a friend with allergies dropped to try and clean the air of dust. But what she found out through the MAAV system is that she actually made the air much worse because she kicked up more pollutants with her vacuuming and dusting. Realizing 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 is 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."

Researchers also learned that circumstances that made the air pollution worse differed in each home. Vacuuming in the home, for example, would cause different reactions to the air quality. They also learned that if homeowners could visualize the air quality in their home, they always stayed on top of labelling and looking at the data.

The findings appeared in the Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Tech.