Acid rain is primarily linked to emissions of which pollutants?

• A. Ozone and carbon dioxide.
• B. Ammonia and methane.
• C. Particulate matter only.
• D. Sulfur dioxide and nitrogen oxides.

Answer: (D)

Acid rain comes from gases that become acids in the atmosphere. The main culprits are sulfur dioxide and nitrogen oxides released when fossil fuels are burned (in power plants, factories, and vehicles). In the air, these gases react with water, oxygen, and other chemicals to form sulfuric acid and nitric acid. When rain, snow, or fog forms, these acids dissolve in the precipitation, lowering its pH and creating acid rain.

Ozone and carbon dioxide aren’t the primary sources of the acids that cause acid rain. Ammonia and methane are important pollutants for other environmental reasons, and particulate matter can influence deposition patterns, but the direct formation of acid rain mainly involves sulfur dioxide and nitrogen oxides.