Portland, Ore. where air quality is improving (Credit: Cacophony, via Wikimedia Commons)
A study by the American Lung Association finds that Oregon air quality is improving, according to the Statesman Journal.
Study authors evaluated particle pollution and ozone figures from EPA reporting stations available for 2010, 2011 and 2012. They found that the area between Salem and Portland has some of the cleanest air in the country.
The region is also one of the cleanest in terms of short-term particle pollution. Short-term ozone levels are likewise low when compared to those in other areas of the country, but have been exacerbated by heat waves in recent times.
Image: Portland, Ore. where air quality is improving (Credit: Cacophony, via Wikimedia Commons)