Which pollutants are primarily associated with acid deposition via long-range transport?

• A. PM and ozone.
• B. Sulfate and nitrate from sulfur and nitrogen pollutants.
• C. Methane and nitrous oxide.
• D. Carbon monoxide and lead.

Answer: (B)

Acid deposition that travels long distances mainly comes from sulfate and nitrate formed when sulfur dioxide and nitrogen oxides from fossil-fuel burning oxidize in the atmosphere to create sulfuric and nitric acids. These acids form sulfate and nitrate particles and can be carried far from their original sources before being removed by precipitation or dry deposition. This long-range transport is why sulfate and nitrate are the pollutants most closely associated with acid deposition. Other listed pollutants affect air quality or climate in different ways and aren’t the primary drivers of long-distance acid rain.