There's another reason to hate kudzu, the invasive vine that has swallowed huge swaths of the South: It might make our air harder to breathe.
That's according to a study by researchers from the University of Virginia, Columbia University and Harvard University.
The study of kudzu patches in rural Madison County in Northeast Georgia found that ground planted with kudzu leaked enough ozone-causing gas to trigger a 50 percent increase in the number of days each year in which ozone levels exceed what the U.S. Environmental Protection Agency deems healthy.
And since Chattanooga has long battled the EPA over local air quality, and the region's hills are packed with curly kudzu, one might think killing off the vine could clean up our air.
But Chattanooga has something that Madison County doesn't: massive amounts of car and truck traffic.
The trucks and cars on local roads pump out far more ozone-producing gas than kudzu could ever match, said study author Jonathan Hickman, a research fellow at Columbia University.
"It's highly unlikely that kudzu is currently having a measurable impact on air quality in and around Chattanooga," Hickman said.
Local air quality watchers say the same thing.
"We've known for years that kudzu could be a factor," said Bob Colby, director of the Chattanooga-Hamilton County Air Pollution Control Bureau. "But our biggest factor when looking at air quality are cars and trucks."
What makes kudzu different from other plants - such as grasses, weeds and trees - is that it produces the chemicals isoprene and nitric oxide. Those chemicals combine with nitrogen in the air to form ozone, a pollutant that causes significant health problems for people.
But Colby said there isn't much reason to soak the hills in Roundup because the improvement would be minimal.
On top of that, kudzu roots are made for self-preservation, Hickman said. They grow big, fat and deep to lock in nutrients and can take years to kill back, even with the most potent herbicide.
Still, given how kudzu grows, controlling its spread is something the city should plan for, said Chattanooga City Forester Gene Hyde.
"As a forester, I was trained to think long-term," Hyde said. "Looking 20, 30, 40 years out, and even long after I'm gone, you have to wonder how big these patches are going to get."
Given that kudzu smothers other plant life and now is known to harm the air - even just slightly - there's reason to prevent the invasive intruder from spreading beyond its current 7 million acres across the United States, said one of the study's authors.
"This is yet another compelling reason to begin seriously combating this biological invasion," said study co-author Manuel Lerdau of the University of Virginia. "What was once considered a nuisance and primarily of concern to ecologists and farmers is now proving to be a potentially serious health threat."
Contact Adam Crisp at acrisp@timesfreepress.com or 423-757-6323. Follow him on Twitter at twitter.com/adam_crisp.