Summary
Highlights
Acid rain has natural sources like rotting vegetation and volcanic eruptions, but human activities, such as burning fossil fuels, vehicle emissions, and factory chemicals, are the primary contributors.
Normal rain is slightly acidic (pH 6) due to dissolved carbon dioxide forming carbonic acid. However, burning fossil fuels releases sulfur dioxide and nitrogen oxide, which react to form sulfuric acid and nitric acid, significantly increasing the rain's acidity (down to pH 3).
Acid rain has severe ecological effects, particularly on aquatic environments. It increases water acidity, leading to more aluminum absorption from the soil, making it toxic for aquatic animals. It also damages forests by harming leaves, stripping essential nutrients from the soil, and impeding water consumption by trees.
Reducing the burning of fossil fuels is a key step to lessen the pollutants responsible for acid rain. Acid rain also damages buildings, monuments, and statues, especially those made of limestone and marble, due to reactions between the calcium compounds and the acid in the rain. An example is the Taj Mahal, which was affected by exhaust gases from the Mathura refinery.
Acid rain is a phenomenon where sulfur dioxide and nitrogen oxide gases react with water and oxygen in the atmosphere and fall back to earth as acidic precipitation. It can occur as wet deposition (rain) or dry deposition (dust or gases).