A geoscience professor at Georgia State University says his research confirms the Clean Air Act of 1970 led to increased rainfall in Atlanta.

Jeremy Diem analyzed summer rainfall data from nine weather stations in the Atlanta metropolitan area from 1948 to 2009 and fund precipitation increased markedly in the late 1970s as pollution decreased following passage of the Clean Air Act of 1970.

Diem said pollution in the 1950s and '60s caused rainfall to drop in the Atlanta area, a university release said Wednesday.

Previous studies have found a general link between air pollution and rainfall, with rainfall being suppressed with higher concentrations of particulates in the air.

The findings -- that a substantial decrease in pollution in a specific metropolitan area can cause an increase in rainfall -- are likely to apply to other urban areas across the United States experiencing similar pollution decreases, Diem said.

"Really, the only plausible reason for this increased rainfall is the reduced pollution due to the passage of the Clean Air Act," Diem said. "This probably happened in many cities other than Atlanta."