Long-term study shows acid pollution in rain decreased with emissions
"We still have acid rain. Yes, the trend is down, and we should celebrate that, but it's still a problem. There is still progress to be made, and there are new regulations coming along to continue to reduce emissions of sulfur and nitrogen compounds."
- Christopher Lehmann, a researcher in the program
Emissions regulations do have an environmental impact, according to a long-term study of acidic rainfall by researchers at the University of Illinois.
According to EPA data, sulfate emissions dropped more than 50 percent during the period covered by the study and nitrate emissions dropped more than 30 percent.
The National Atmospheric Deposition Program report found that concentrations of corresponding acid ions in rainwater have dropped by similar magnitudes. In addition, frequency of acidic precipitation has decreased across the U.S.