Is the Air Worse Inside or Out?

It’s easy to only pay attention to the quality of air outside, not inside, especially when the air quality index (AQI) suffers from high concentrations of noxious, cancer-causing polycyclic aromatic hydrocarbons (PAHs) from wildfires – which Oregonians have had their fair share of over the last few years. Under conditions like those, it’s easy to forget that the quality of indoor air can actually be worse. 

Oregon State University’s Kim Anderson, an environmental chemist, recently spoke with KLCC about the issue of indoor air, saying, “[E]ven when we see AQI numbers like 150 for example, the indoor air for these classic compounds called PAHs, are higher than outdoors. Specifically, AQIs oftentimes are really focused on particulate matter, but PAHs can exist both on the particulate, and they can be as a gas that we breathe.” 

Anderson conducted tests on air quality during the 2018 wildfire season. “People think air inside their house is perfectly clean, and that if we close all the windows when it is smoky outside there will be zero contaminants inside. That’s just not true,” she said in a press release from OSU in 2020.  

What most people don’t understand is that PAHs can be very small, and can seep into your house. Therefore, Anderson conducted an experiment where she placed air samplers inside and outside of buildings during fire season. The PAHs from inside were equal to or greater than from those outside.  

It was also found that PAHs can come from cooking, burning candles, and air fresheners. So don’t be afraid to open your windows and let the not always completely clean air in. It’s for your own health.  

By John M. Burt