Mild, mainly cloudy summer has kept smog levels at bay in Western Pennsylvania
Pittsburgh-area residents can breathe a little easier this summer, because mild temperatures and heavy cloud cover reduced the number of days air quality dipped to a dangerous level.
There have been zero “Air Quality Action Days” in the Southwestern Pennsylvania region so far in 2014. Those are days in which ground-level ozone levels are high enough that the air is unhealthy to breathe, said Department of Environmental Protection spokeswoman Lisa Kasianowitz.
“We've had such a mild summer, there have not been a lot of days that have reached 90 (degrees),” she said. “You need sun and hot temperatures to form ozone from pollutants.”
Ground-level ozone occurs when pollution near the ground gets “baked” by sun and high temperatures to form ozone, also known as smog.
Average temperatures in July and August have been about 2 degrees lower than normal, said Brad Rehak, a meteorologist at the National Weather Service office in Moon. Forecasters expect this weekend to be warmer, with sun and predicted highs of 82 on Friday and 88 on Saturday, but Kasianowitz said DEP staff don't expect either would generate enough ozone to trigger an action day and break the region's streak.
The Liberty-Clairton area, which gets separate forecasts from the rest of the region because it's in the Monongahela River Valley and close to heavy industry, has had only one day this year (in February) in which particulate matter, or PM-2.5, has risen to trigger a DEP alert, Kasianowitz said.
The DEP issues a PM-2.5 alert when tiny pollution particles from engines and industry cling to moisture in the air and form a haze, Kasianowitz said.
“It's complicated, but we have been seeing a slow and steady decrease from the places with emissions that lead to ozone,” said Jamin Bogi, policy and outreach coordinator for the Group Against Smog and Pollution, a nonprofit air-quality advocacy group. “That trend is working in our favor.”
Improving vehicle emission standards and either shutting down coal power plants or reducing their emissions have helped to lower the levels of pollutants in the air that can form ozone.
James Fabisiak, an associate professor at the University of Pittsburgh's Department of Environmental and Occupational Health, said the weather helped reduce the number of action days, but he noted that people with breathing problems or weakened immune systems still could be at risk.
“Even the smallest doses we can measure still seem to have an effect,” Fabisiak said. “The risk decreases as the dose goes down, but we can't say there's a point where the risk is negligible.”
The Environmental Protection Agency uses a three-year average of air quality action days to measure a region's health. It is set to re-examine and possibly lower the threshold for ozone action days in the region, Bogi said.
“We're happy — this means healthier citizens, at least over the last few months,” he said. “We just have to keep our eyes on the ball.”
Matthew Santoni is a Trib Total Media staff writer. He can be reached at 412-380-5625 or firstname.lastname@example.org.
Add Matthew Santoni to your Google+ circles.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.
- Lowly job likely awaits former Pittsburgh police chief after prison
- Governor decries low voter turnout for primary election
- Grand jury investigating Plum sex scandal involving possibly 8 students
- Pedestrian struck, killed by train in Coraopolis
- Feds want to seize cash, property from suspects in drug bust
- Pennsylvania Sen. Casey seeks to provide aid to repairing locally owned bridges
- Analyst says Pa. senate race leans toward Toomey — because Democrats ‘loathe’ Sestak
- Police charge suspect in fatal shooting in Jefferson Hills
- Millions to travel through Western Pa. during Memorial Day weekend
- DOJ program goal: Increased trust between law enforcement, community
- ‘Sham’ cancer charity penalized by regulators had been sued by Pa.