Idling cruise ships have been identified as major contributors to air pollution in Charleston | Photo courtesy of Charleston Communities for Cruise Control/C4

More than 137 million people in the U.S. live in counties with unhealthy levels of air pollution, according to a new report from the American Lung Association (ALA) that analyzed air quality from 2018-2020. 

The ALA’s State of the Air report released today looked at two buckets of air pollution — ozone and particle pollution — and particle pollution breaks down further to short-term and year-round pollution. Year’round pollution is a day-to-day experience, while short-term refers to spikes of anywhere between 24 and 72 hours. 

Charleston’s air quality saw some improvements, according to the report, some of the best ever measured in the city, in fact, according to ALA’s S.C. senior director of advocacy Ashley Lyerly.Overall, the Lowcountry saw fewer unhealthy days for ozone pollution, and improved significantly  in year-round particle pollution.

However, Charleston did see more unhealthy days in terms of short-term spikes in particle pollution. This led to the Holy City being entirely left off the ALA’s “Cleanest Cities” list for 2022. Charleston failed to crack the top 64 in terms of ozone pollution, and didn’t even make the top 80 in particle pollution. The only two cities in South Carolina that even made the “Cleanest Cities” list are Florence and the Conway/Myrtle Beach area. 

“Previously, Charleston had ranked among the cleanest in the nation, but it didn’t make that cut this time period,” Lyerly said. She explained that with Charleston acting as a commerce hub in the state, and the uptick in shipping during the onset of the pandemic in 2020, idling container ships and home delivery of goods may have driven the steep rise in short-term particle pollution. 

“We have seen a tremendous shift in consumer behavior in both how we send and receive goods,” she said. “Whether it’s shipping goods and having a motor vehicle deliver it directly to our homes, some of that behavior can explain the worsening of air quality

Some of the change in air quality can also be attributed to climate change, Lyerly said. Higher temperatures over longer periods of time and more frequent stagnation events play a significant role in making the number of unhealthy ozone days higher than it would otherwise be, the report reads. Although cleanup of ozone-generating pollutants has helped reduce ozone concentrations, the warming wrought by climate change, put simply, is undercutting progress that has been made. 

Emissions from vehicles play perhaps the most prominent role. Charleston’s Climate Action Plan, adopted in May 2021, outlines a plan to transition the city’s fleet of vehicles to new, electric models to stave off emissions — a move that will help clean up the air in the Lowcountry. 

“It would have a significant impact,” Lyerly said. “The transition to net-zero-emission vehicles would have a clear impact on air pollution in Charleston and broadly, if we see similar changes nationally.”

Charleston began the early stages of transitioning the city’s vehicle fleet to electric models in March 2021, seeking grants to purchase two electric garbage trucks. Later, support for shore power and electric vehicles for use at ports was written in the city’s Climate Action Plan. In a move likely to help this transition, Charleston’s Mercedes van plant will begin producing electric Sprinter delivery vans in 2022. 

Lyerly said a lot of work at the national level is left to be done as well, such as implementing the Clean Air Act and other climate legislation that can trickle down to states and local communities. 

“The first look at air quality trends — we aren’t seeing the obvious improvements we thought we might see because of less people on the roads,” Lyerly said. “It may be a little too early to draw correlations between air quality and the impact of the pandemic. We may have something different next year.”