Experts say air conditioners could be trapping, recirculating particles from wildfire smoke
Air quality is improving in Chicago compared to last week.
Experts, however, say just because the smoke is leaving the sky doesn't mean it's leaving people's homes, as air conditioning units may be trapping some of those hazardous particles.
Hazy skies started the week, putting the city back at number one for worst air quality in the world by Monday morning.
Though not to be compared with last Thursday, there's now a concern that without proper filtration indoors, the harmful air can stick around much longer.
"People want to feel safe in their homes, and our data shows that they were not safe in this instance," said Joshua Rogers, president of Alertify. "We have a sensor ... plugs into your wall, and sends data about air quality, about sound levels, about dangerous chemicals."
Alertify tracked data from their sensors in 31 apartments with central air conditioning in five multi-family buildings in Chicago from last Tuesday morning until Monday.
"So when the air quality was sort of 600 to 700 AQI, it was actually around 340 in the apartments that we monitored," Rogers said. "We found that the levels of particulate matter indoors were also very, very high, shockingly high. Actually, in this case, in fact, we'd never seen levels like this that come from exogenous sources."
Data showing that even when the outdoor air improved, the air indoors didn't.
Experts say there is a common misconception that air conditioning units filter the air, but instead, it pulls in outside air and recirculate particles that have settled indoors.
"You can upgrade a filter in your home from, you know, there's certain levels, and if you get like a 13 or a 14, that'll do a much better job of filtering out this type of particulate matter," Rogers said.
Some organizations are partnering with the Chicago Department of Public Health.
"This is a global issue, it's a national issue," said Dr. Alex Sloboda with CDPH.
On a project that could help study the long-term health impact from days of pollution exposure.
"There are hundreds of sensors throughout the city that are on a daily basis monitoring for these similar pollution particles that we've seen from the wildfire to help inform those communities," Dr. Sloboda said.
