Air Pollution Control Laws in North America and the Problems of Acid Rain and Snow
Recent scientific evidence has made it clear that air pollution emissions may have environmental effects in regions much more distant from the source than previously believed possible. Oxides of sulfur and nitrogen produced in the burning of fossil fuels and in smelting operations may be carried hundreds or even thousands of miles through the atmosphere, chemically transformed in the process, and eventually returned to earth as sulfuric and nitric acids, often in rain or snow.