Allegheny County meets the air high quality commonplace for the primary time in many years

After falling behind most of the country for decades, Allegheny County has managed to meet the federal minimum health standard for one of the most harmful of the major air pollutants.

Particulate matter pollution, known as PM2.5, averaged 11.1 micrograms per cubic meter of air over the past three years, bringing the county’s average below the federal standard of 12. It is the first time the county’s three-year average has hit the average standard since it was established by the US Environmental Protection Agency more than 20 years ago.

The county’s PM2.5 emissions have long been determined by high readings from a monitor in Liberty Borough off the wind from the US Steel Clairton Coking Plant in the Monongahela River Valley. Last year, emissions fell to record lows in Liberty with the help of the COVID-19 pandemic.

“It’s good news because it’s showing improvement,” said James Kelly, assistant director of environmental health for the Allegheny County Health Department. “But there is still more to be done.”

For example, it is unclear how a return to normal business operations will affect vehicle and industrial emissions, which have decreased during the pandemic. County aviation officials note more frequent weather-related episodes that trap the pollution for days. And a recent EPA health risk analysis shows that the PM2.5 standard, which the county has just met, has gained momentum.

Persistent problem

PM2.5 is one of the most dangerous air pollutants in the world. It consists of microscopic particles and can only be seen in high concentrations when it appears as a haze.

When inhaled, the particles easily get into the lungs, bloodstream and other organs. A large body of scientific research links PM2.5 exposure to a higher risk of heart and lung disease and premature death. The particles can linger in the air for a long time and travel hundreds of kilometers.

Allegheny County and southwestern Pennsylvania have struggled more than most regions in the country to tame air pollution. For two decades, PM2.5 concentrations in the county were among the worst in the nation, putting public health at risk and tarnishing the region’s reputation as one of the best places to live in America.

Sources of pollution include emissions from industry in the region’s river valleys and from non-state power plants off the wind, especially those that burn coal. Road vehicles are another source of emissions that PM2.5 can create. And frequent temperature reversals common in the region, which trap the pollution, keep those emissions for days.

Air pollution in the area has been greatly reduced in recent years, but most other metropolitan areas in the United States have done better.

The PM2.5 pollution recorded on the county’s Liberty Monitor last year was less than half its 2000 level – the result of years of technological advancement, advocacy, tougher regulations, local enforcement, industrial and economic investments Factors.

This has helped the district’s three-year average of PM2.5 emissions meet the federal minimum health standard. If the EPA confirms the data as expected later this year, the county will be classified as a “hit” for the first time – something 99.5 percent of more than 3,000 states, including all other counties in the United States, have already achieved Pennsylvania.

Economic and travel disruptions caused by pandemics helped reduce these emissions last year. For example, one battery at the Clairton coking plant has been put on “hot idle” and almost all of the others have a longer coking time, which also reduces emissions, Kelly said.

However, emissions from both local and non-governmental sources are already so low that the county would have hit PM2.5 even without the help of the pandemic, he said. “The backbone of our power grid was once primarily coal-fired [power plants]. Now it’s overwhelmingly natural gas fueled. This is a major reduction in emissions, which are regionally among the largest emission factors. “

In Allegheny County, concentrations of ground-level ozone pollution fell to federal standards a few years ago. Ozone, caused by a reaction between sunlight, heat, and fossil fuel emissions, damages lung tissue and can exacerbate respiratory diseases such as emphysema and asthma. Car, truck and bus emissions are among the largest catalysts.

Pittsburgh Works, an industry and working group, argued in a recent report that such improvements believe the air in the area ranks poorly in some national comparisons, such as the American Lung Association’s annual air quality ranking. The group describes the air quality of the region as “more like a“ C + student ”.

Unfinished business

Regardless of the degree, the region is still in the works when it comes to protecting the public from the health risks of air pollution.

Allegheny, Armstrong, and Beaver Counties do not meet minimum health standards for the air pollutant sulfur dioxide – something 98 percent of U.S. counties have already achieved. Emissions trends suggest Allegheny County could achieve that status this year, health officials said.

County air quality officials report an increase in the frequency of weather conditions that prevent the spread of pollutants, leading to more intense concentrations and greater health risks.

A new rule from the county’s Department of Health is expected to come into effect later this year, requiring industry and others to take immediate action to reduce emissions when such days occur. “It’s a similar idea to saying it will be a high ozone day. Please refill your car later in the day or don’t burn your yard until we have better air quality,” said Jayme Graham, Head of the Ministry of Health’s air quality program.

And scientists continue to debate whether U.S. air quality standards are protecting human health the way they need to be. “There is a huge gap between regulatory standards and what public health experts set as the standard that actually protects people,” said Matthew Mehalik, director of the Breathe Project, a coalition of environmental, health and academic organizations.

For example, the EPA’s most recent PM2.5 standard that the county has just met says pollution is 20 percent above the limits set in Canada and recommended by the World Health Organization for all nations.

In an internal analysis of the U.S. PM2.5 standard last year, EPA scientists questioned the protection it offered the public and presented a case where the annual limits of 12 micrograms per cubic meter of air fell to 10 or lower to better reflect the public health risk. No change was made. However, the new EPA administration is expected to reconsider the growing evidence suggesting that lowering PM2.5 leads to fewer deaths, increased life expectancy, lower rates of respiratory disease in children, and other health improvements.

Stricter limits on air pollutants would again challenge the region to find new ways to purify the air for better health and quality of life. “As Pittsburghers, we pride ourselves on the history of innovation in our region,” said Mehalik. “We can find a way to get way ahead instead of being a backward region on a very important public health issue that affects every resident and business in the county.”