Origins of the term
The phrase "acid rain" comes from Robert Angus Smith, a chemist in Manchester who noticed in 1852 that rain in industrial districts was unusually acidic and laid out the idea systematically in his 1872 book Air and Rain. Coal smoke from the Industrial Revolution was to blame. The issue went international in the late 1960s, when Swedish scientist Svante Odén argued that smoke from British and German factories was drifting hundreds of kilometers to acidify Scandinavian lakes, making cross-border pollution a political question for the first time. In 1974 Gene Likens and F. Herbert Bormann reported acidified rain over New Hampshire's forests.
Causes and damage
Even clean rain is slightly acidic, around pH 5.6, because carbon dioxide dissolves in it. When sulfur dioxide and nitrogen oxides from power plants, steelworks and vehicles turn into sulfuric and nitric acid in the air, rain can drop to about pH 4. Lakes in Scandinavia and North America lost their fish, and in 1980s Germany "Waldsterben," or forest death, became a national concern. Acid rain also eats away marble statues and old buildings and leaches aluminum from soil that damages tree roots. The same emissions are precursors to secondary fine particulate matter.
Regulation and recovery
Europe signed the Convention on Long-Range Transboundary Air Pollution in 1979, and the 1990 US Clean Air Act Amendments created a sulfur dioxide cap-and-trade market that sharply cut power-plant emissions. With scrubbers and low-sulfur fuel, acid rain in Europe and North America is far weaker than in the 1980s, though acidified lakes take decades to recover, and East Asia is improving as coal use falls. Like the ozone layer, acid rain is often cited as proof that international regulation works, and cutting fossil fuels today ties into net-zero policy.
FAQ
- Can acid rain make your hair fall out?
- There's little scientific basis. Modern rain is far less acidic than lemon juice or many shampoos, and hair loss is driven mainly by genetics, hormones and stress. Washing your hair after rain is enough.
- Is acid rain still a problem?
- It's much reduced in Europe and North America, but rain remains mildly acidic in many industrial regions, and damaged lakes and soils are still recovering.
Sources reviewed: 2026-10-26
References
- Smith, R. A. (1872). Air and Rain: The Beginnings of a Chemical Climatology. London: Longmans, Green.
- Likens, G. E., & Bormann, F. H. (1974). Acid rain: a serious regional environmental problem. Science, 184(4142), 1176–1179.
- Menz, F. C., & Seip, H. M. (2004). Acid rain in Europe and the United States: an update. Environmental Science & Policy, 7(4), 253–265.