Blame Allegheny County’s poor air quality forecasts on a weather event called an “inversion” where warm air in the atmosphere traps cold, polluted air on the ground.
Or blame the polar vortex.
While county health officials predicted a poor air dispersion day that didn’t quite materialize Tuesday, another is in the forecast for Wednesday.
Jim Kelly, deputy director for Allegheny County Health Department’s Environmental Health, faulted the quick temperature warm ups for the air quality concern. In the past week, the region has been slammed with a wild, 80-degree-temperature swing, that includes wind chill, exasperating Pittsburgh’s air quality.
Inversions can happen with a cold summer night, but generally hits the area in late fall.
“With the occurrence of polar vortexes, it happens more frequently,” Kelly said of the weather inversions.
Last February, Allegheny experienced a quick warm-up that resulted in three days of similar conditions and air quality concerns. This weather event, however, has struck “every day since Friday night,” Kelly said.
Kelly added, “This is exceptional. It is really bad for air quality.”
On Monday, the Pennsylvania Department of Environmental Protection placed 20 counties – including Allegheny, Armstrong, Beaver, Butler, Fayette, Washington and Westmoreland – under a code orange quality action day alert for fine particulate matter. Those with respiratory issues such as asthma, bronchitis or emphysema as well as the young and elderly are particularly vulnerable and should limit outdoor activities on air quality action days.
Matt Mehalik, executive director of Breathe Project, a Pittsburgh organization committed to providing information on air quality issues in southwestern Pennsylvania, took issue with the county’s explanation. He said weather events amplify, but don’t cause, pollution.
“The air pollution isn’t coming from the polar vortex,” said Mehalik, noting the county has failed to submit to the U.S. Environmental Protection Agency a control strategy for particulate matter. “It comes from local sources of pollution in Allegheny County.”
Nicole Brambila is a Tribune-Review staff writer. You can contact Nicole at 724-226-7704, nbrambila@tribweb.com or via Twitter @nbrambila.
