AUSTIN (KXAN) — When pollution levels become a problem outside, usually you can bet that some of that bad air would get indoors.
Still, it’s generally considered safer to breathe the air indoors if pollutant levels outside are high since AC/heating unit filtration systems help mitigate pollution coming inside.
A new study from the University of Utah found indoor pollution levels aren’t reduced the same across varying pollutants when compared to their outdoor levels. Said another way: certain outdoor pollutants are better at getting indoors than others.
Researchers found that high pollution levels caused by an inversion (where warmer air higher up in the atmosphere traps bad air near the surface) did not significantly increase pollution levels indoors. It’s not believed that the environmental factors that trigger inversion outdoor pollution exist indoors — therefore pollution levels are much lower. In the study, tracking indoor and outdoor pollutant levels, indoor pollutants were 30% of the levels of outdoor pollutant levels.
Indoor pollution from nearby fireworks displays were also shown to be at levels 30% of those outside.
But when looking at pollution from wildfire smoke, getting indoors did not provide nearly as much relief. The study found indoor pollution levels after a nearby wildfire were as high as 78% of outdoor levels. Smoke particles are smaller in size and have an easier time moving through filters and into homes compared to other pollutants.
If you or a loved one have asthma and are particularly sensitive to pollutants, knowing what’s causing the pollutant can inform you about the type of relief you may find by staying indoors. In all cases, however, being indoors still provided at least some relief from higher pollutant levels outdoors.