The Pennsylvania Department of Environmental Protection (DEP) is warning children, the elderly and those with respiratory issues to limit outdoor activities in the Pittsburgh area Thursday.
The DEP issued a code orange air pollution alert for five Pennsylvania regions.
The pollution comes from an overabundance of ground-level ozone, a fundamental element of smog. The ozone forms during hot, sunny days when pollution from cars, factories, homes and power plants mix with nitrogen oxides in the air, causing people to breathe in the volatile organic compounds.
Pennsylvania DEP spokesman Kevin Sunday said areas with high population densities are at the greatest risk for air pollution.
“With vehicle traffic, power plants and gasoline vapors being some of the leading contributors to ozone precursors, you’re going to expect those to correlate very closely with population areas,” Sunday said.
The U.S. Environmental Protection Agency uses a color coded air quality index that Sunday said “takes the heavy science out of the equation” and makes it more accessible to the public. The index runs from green to red, with orange being a step down from the most severe pollution alert.
Sunday said these alerts are day-to-day with no way to tell how long they will last.
He said the best way to reduce air pollution on days like this is to be conscious of your energy choices.
“Using energy efficient equipment in your house — and appliances — certainly helps, being more efficient with vehicle use such as carpooling, combining trips or even exploring the use of an alternative-fueled vehicle, whether that’s a plug-in hybrid or a natural gas vehicle,” Sunday said.
Sunday advises people to reduce ground-level ozone by refueling vehicles at night so gasoline fumes don’t bake in the hot sun, cutting down on car trips, turning off lights when they aren’t being used and only doing full loads of laundry.
Lehigh Valley, Liberty-Clairton, Susquehanna Valley areas and Philadelphia are also under orange air quality alerts Thursday.