The researchers found that there were nearly 400 fewer hospital admissions or emergency room visits for asthma attacks in Louisville in the year following the closure and the addition of pollution controls.
The study also included data from a fourth coal-fired plant that added scrubbers in Madison, Indiana, in 2013, also separately owned.
Rockport is about 75 miles from Louisville, and Madison is about 55 miles away.
Casey said that there have been numerous studies showing that people who live near coal-fired power plants have more asthma symptoms and other maladies.
Indiana was still reliant on coal for 70 percent of its electricity in 2018, according to the U.S. Energy Information Agency.
Louisville also has its own air pollution control district, and it's seen local power plant pollution drop sharply.
"It will be incredibly gratifying to see those emission reductions translate into improved health outcomes in our community. »