OGDEN — When pollution settles over Utah's valleys in the wintertime, sometimes creating the dirtiest air in the country, some residents don breathing masks to protect themselves.
But experts say they aren't necessarily a cure-all, the Standard-Examiner reports.
The masks usually aren't tight-fitting enough to protect a person's lungs and they don't have filters fine enough to stop the tiny particulate matter that is harmful.
If they fit both categories, a person would struggle to breathe while doing physical activities.
That's why the Utah Division of Air Quality doesn't make any recommendations about masks.
"Our employees who use respirators are under medical monitoring to determine if they are in good physical condition before using a negative pressure respirator," Director Bryce Bird said in an email provided by the division. "The use of these products are a personal choice that should consider the physical fitness of the individual."
The Centers for Disease Control and Prevention has a list of manufactures selling respirators that remove 95 percent of fine air pollution particles, but does not endorse any.
"It's really hard to find a satisfactory solution," said Brian Moench, an anesthesiologist and president of Utah Physicians for a Healthy Environment.
He said people would be better off buying air purifiers for their bedrooms.
Moench also recommends biking or walking on bad air days even thought that might seem counterintuitive.
"People who are driving and exposing themselves to traffic congestion, they're typically breathing whatever is coming out of the exhaust of the cars in front of them," Moench said.
Northern Utah has endured heavy pollution this winter from winter inversions caused by weather and geography.
The inversions are a phenomenon in Utah's urban corridor caused when cold, stagnant air settles in the bowl-shaped mountain basins, trapping tailpipe and other emissions that have no way of escaping to create a brown, murky haze the engulfs the metro area.