Literally it means the presence of excessive acids in rain water or the fall of acids mixed with rain and snow. ... H2SO4 is the major contributor (60-70 percent) to acid precipitation.

H2SO4 supply is in part involuntary: metal smelters producing it instead of acid rain. If you want a good leading indicator look at the construction sector, never disappoints you.

As a result of its reaction with hydroxyl radicals, sulfuric acid (H2SO4) is formed starting from SO2 and methanesulfonic acid (MSA), which play a major role in the formation of natural particles ...