There's an air quality alert in Lancaster County today. So what does that mean?

Particle pollution comes from a variety of sources such as cars, power plants, factories, construction sites, forest fires, and municipal waste incinerators. 

Breathe easy, Lancaster County. Just don’t breathe too deep. The level of ozone pollution, which is especially harmful to children, the elderly and the 55,000 residents with asthma, has fallen to barely passable levels here, according to a new report. The amount of soot we’re inhaling has declined for the third consecutive year, as well.

Lancaster now ranks 20th on the list of the 25 most polluted cities in the nation, an improvement over last year’s 16th-place ranking by the American Lung Association.

“Except for the problem of daily spikes in fine particle pollution, people in Lancaster County are breathing even better quality air,” Deborah P. Brown, president and CEO of the American Lung Association of the Mid-Atlantic, said in announcing the findings of the annual “State of the Air” study.

The findings represent welcome improvements in Lancaster County’s historically poor air quality. But they also underscore how much work remains to be done.

It is notable, for example, that the county earned a passing grade — a “C” — in smog pollution for the first time in the 18 years researchers have been conducting the “State of the Air” studies.

Lancaster County still ranks as one of the worst in the nation, though, when it comes to the average number of days with high levels of soot, increasing from last year’s 8.8 days to 9.2 days. The soot levels were worse here than in any other county east of the Utah, the report stated.

Ozone a bit worse

The county ranked 84th in number of days when ozone concentrations are dangerously high out of 228 metropolitan areas, according to the report. Last year it ranked 82nd.

Soot has dropped nationally in year-round levels, according to the report; however, the tiny particles that are brought about by coal-fired power plants, diesel engines, wildfires and wood-burning devices are still susceptible to short-term spikes. Those spikes have increased nationwide.

Lancaster’s metro area ranks 12th worst in the nation for short-term soot. It ranked 11th in this category in last year’s report.

Harrisburg-York-Lebanon, lumped together as one metropolitan area, ranks 21st worst in short-term soot and 22nd in annual totals.

“The report found continued improvement in air quality across the country, but 40 percent of Americans still live with unhealthful levels of either ozone or particle pollution placing their health at risk,” Brown said.

The 2017 “State of the Air” report covers data collected by states, cities, counties, tribes and federal agencies from 2013 to 2015.

Local factors

The Pennsylvania Department of Environmental Protection cites numerous meteorological and emissions factors as influences to air quality in the county.

The factors include a high number of farms in the eastern part of the county, which leads to a high flux rate of ammonia and “particulate from local traffic and choice of heating source,” the DEP said in an email.

A reduction, or elimination, of fireplace and wood stove use, as well an avoidance of burning leaves, trash and other materials, would help the the county improve its air quality, the DEP said.

“Ozone is harmful to public health and especially children, older adults and those with asthma and other lung diseases,” Kevin Stewart, director of environmental health at the American Lung Association of the Mid-Atlantic, said in the news release. “When they breathe ozone-polluted air, too often they end up in the doctor’s office, the hospital or the emergency room.”