A pair of scientific reports out this week looked at air pollution and how it’s changed in recent years. The Mountain West looks clean compared to other parts of the country, at first glance.
The researchers looked at a certain category of polluting particles that are especially worrisome for health. They’re called PM 2.5 for their size, which is small enough to penetrate lung tissue and get into the bloodstream.
The World Health Organization has set a guideline for the concentration of PM 2.5 deemed less harmful to people. Researchers found that in 2015, counties in the Mountain West tended to be at or below that level -- but not all the time.
“The Intermountain West is a little bit tricky in that we have some of the cleanest air in the nation and we have some of the most polluted air in the nation,” says Arden Pope, an economist and epidemiologist at Brigham Young University.
Basically, he says, our air pollution goes through dramatic swings. On days when the air is moving, we have good air quality. On days where the air is trapped, stagnating over cities, we end up with high concentrations of pollutants.
“This happens in the Salt Lake City area, happens in Boise, happens in Denver, happens even in Las Vegas,” says Pope.
According to analysis by the group Climate Central, hotter summers are expected to bring more days of stagnant air. The silver lining is that, contrary to trends in other parts of the country, the number of stagnant air days in the Mountain West appears to have fallen over the past few decades.
In other positive news, Pope says cities like Boise, Salt Lake City and Las Vegas stand out for improving their air quality in recent years.
After analyzing about 15 years of data on air quality and health, the researchers concluded that lowering PM 2.5 concentrations even further could lengthen the life expectancy of the average American by about 50 days.
A separate reportlooking at a different health dataset reiterate the correlation between better air and health. Writing in the journal Environmental Health Perspectives, researchers including Pope concluded that long term exposure to PM 2.5 is associated with a higher risk of death due to heart and lung problems.
“The whole idea was to try to see if we could see these kinds of health effects in different types of study designs using different data, and the answer has turned out to be, ‘Absolutely yes’,” says Pope. “It’s very clear that improving air quality results in improved health.”
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, KUER in Salt Lake City, KUNR in Nevada and KRCC and KUNC in Colorado.
