- Definition – Acid rain is a type of precipitation that contains high levels of sulfuric acid and nitric acid, which are formed when sulphur dioxide (SO2) and nitrogen oxides (NOx) released into the atmosphere from human activities such as burning fossil fuels react with water vapour, oxygen, and other chemicals.
- Formation: Sulphur dioxide and nitrogen oxides are released primarily from industrial processes, vehicle emissions, and the burning of fossil fuels such as coal and oil. These pollutants undergo chemical reactions in the atmosphere to form sulfuric acid (H2SO4) and nitric acid (HNO3).
- Transport: Once formed, acid rain can travel long distances before being deposited as rain, snow, fog, or dust. Prevailing winds can carry acidic pollutants hundreds or even thousands of kilometres from their original sources, affecting ecosystems far from industrial areas.
- Effects on Environment: Acid rain has detrimental effects on soil, water bodies, vegetation, and wildlife. It can leach essential nutrients like calcium and magnesium from the soil, making it more acidic and less fertile. In aquatic ecosystems, acid rain can lower the pH of lakes and rivers, harming fish, amphibians, and aquatic plants.
- Damage to Structures: Acid rain can corrode buildings, monuments, and infrastructure made of limestone, marble, metal, and concrete. Over time, this corrosion can weaken structures, erode surfaces, and cause irreversible damage to historical landmarks and cultural heritage sites.
- Human Health Impacts: While direct exposure to acid rain is not a significant health risk to humans, the pollutants that cause acid rain, such as sulphur dioxide and nitrogen oxides, can contribute to respiratory problems like asthma and bronchitis. Additionally, acid rain can contaminate drinking water sources, posing health risks to communities.
- Mitigation Measures: Efforts to reduce acid rain include implementing emission controls and pollution prevention measures in industries and transportation, transitioning to cleaner energy sources such as renewable energy and natural gas, and promoting sustainable practices in agriculture and forestry.
- International Cooperation: Acid rain is a transboundary environmental issue that requires coordinated efforts among countries to address. International agreements and protocols, such as the United Nations Framework Convention on Climate Change (UNFCCC) and the Convention on Long-Range Transboundary Air Pollution (CLRTAP), aim to reduce air pollution and mitigate the impacts of acid rain on a global scale.