Days after climate researchers published an article estimating a decrease in global carbon emissions, state environmental officials revealed there have been slight improvements in Lancaster County's air quality, too.
But while the researchers pointed to COVID-19 shutdowns as a likely cause, officials at the state Department of Environmental Protection were less willing to draw that conclusion.
And if the improvements are, in fact, a result of the shutdowns, it's possible they'll be undone soon after government officials reopen the state, according to Brenda Read-Daily, an environmental engineering professor at Elizabethtown College.
“I expect these air quality pollutant levels to go back to normal or near normal once the country completely reopens as industry and vehicular traffic picks back up to pre-COVID 19 levels,” she said.
Speaking regionally, Sean Nolan with the state’s Bureau of Air Quality, pointed earlier this week to a decrease in road traffic and its related pollution emissions, specifically nitrogen dioxide — one of five “major” air pollutants measured by the state.
According to Nolan, nitrogen dioxide concentrations have been lower in Lancaster County and across the state since mid-March, when Gov. Tom Wolf ordered residents to stay at home, shuttering non-essential businesses and schools in a bid to curb COVID-19's spread.
Since then, state data shows that passenger traffic in parts of Lancaster County have fallen as much as 27%. And Nolan said regional air monitoring stations show weekday nitrogen dioxide levels down by as much as 24%.
That's in addition to readings from a Lancaster city monitoring station that shows ozone — also called smog — concentrations down by about 5%, Nolan said.
“Yes, the air quality has improved,” Nolan said. “Now, the question probably should be: Has the air quality improved because of the shutdown? That is a much tougher question to answer.”
Nolan said air quality is highly dependent on weather conditions, including temperatures and cloud cover, which can create and trap different pollutants.
“Spring is generally not a high ozone period,” Nolan said, adding that could be the reason for the low readings, rather than the reduced traffic.
Those unknowns need to be taken into consideration before jumping to any conclusions about changes to overall air quality or climate health, said Kevin Stewart, the American Lung association's environmental health director.
“It's really too early to tell what is going to happen,” he said, guessing hindsight and possibly years of research will be needed before the environmental impacts of COVID-19 are fully understood.
However, in their article, published this week in the journal Nature Climate Change, a group of 13 climate experts credit pandemic shutdowns for a global decrease in carbon emissions as high as 17%. They cited reductions in air and surface travel, as well as pollution-causing industrial work.
Carbon, nitrogen dioxide and ozone are only a few among many pollutants that all intermix to create harmful conditions above Lancaster County, which has had historically poor air quality, said Jim Sandoe, an Ephrata-based member of the Citizens' Climate Control Lobby of Lancaster.
Breathing poor air can have negative health effects, leading to asthma, cardiovascular damage and lung cancer — illnesses a Harvard University study linked to increases in COVID-19 mortality rates.
Sandoe guessed poor air quality could be a factor in Lancaster County's numbers of coronavirus-related infections and deaths, which are much higher than in other parts of the state.
“To me it was very predictable that Lancaster County was going to get slammed,” he said.
Knowing that only slight increases in pollution can lead to higher risk of illness, Kelly Kuhns, Millersville University's nursing department chair, said she guesses slight air quality improvements, even if short lived, could have the opposite effect.
“It only makes sense,” she said.
At the same time, Dr. Alan Peterson, Lancaster General Health's emeritus director of environmental and community medicine, turned his gaze indoors, offering a warning to those staying inside in an effort to avoid the contagious virus.
“Many have gas stoves and the nitrogen dioxide and carbon monoxide from these can increase pulmonary and other issues,” said Peterson, who encouraged the use of air purifiers and proper ventilation.
“Children are particularly at risk of respiratory illnesses associated with gas stove pollution. Gas stoves can make indoor air up to five times dirtier than outdoor air at times.”