ScienceDaily: A new study shows clean-air regulations have dramatically reduced acid rain in the United States, Europe, Japan and South Korea over the past 30 years, but the opposite is true in fast-growing East Asian megacities, possibly due to lax antipollution rules or lack of enforcement.
The U.S. Clean Air Act began requiring regulatory controls for vehicle emissions in the 1970s, and 1990 amendments addressed issues including acid rain. Similar steps in the European Union, Japan and South Korea over the...