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.

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.

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 ...