Some parts of Louisville sounded like a war zone last weekend as fireworks laws were relaxed and residents celebrated the Fourth of July holiday. But all of those fireworks contributed to some of the area’s air quality problems.
There are two main kinds of air pollution: fine particle and ozone. Louisville has been having a number of problems with ozone lately, but this weekend there was also a higher amount of particle pollution in the air from fireworks.
Louisville Metro Air Pollution Control District spokesman Matt Stull says the high level isn’t necessarily caused by the city’s official fireworks, but it seems the sheer number of people lighting explosives over the weekend helped push the reading over the threshold.
“In most cases we’re talking about the amount of people that do them on their own, because we don’t generally see much of an elevated level say for Thunder Over Louisville or if there’s a fireworks show in town,” he said.
Federal law says the city’s particle pollution can’t exceed a certain amount—in this case, it’s 35 micrograms of pollution per cubic meter. On July 3, one of the air monitors picked up a reading that exceeded the standard by 10 percent.
Stull says some of the city’s monitors can tell what kind of pollution contributed to the bad air. This is helpful, because it can help the city petition the Environmental Protection Agency to declare the day was an “exceptional event.”
“In the case of I think 2006, we were able to get the 4th of July omitted from our submission, because the speciation data showed it was 80 to 90 percent fireworks,” Stull said.
The city also has asked for “exceptional event” status for other reasons, like when pollution from wildfires nears Louisville.