Which of the following is a natural source of air pollution?

Volcanic eruptions are a significant natural source of air pollution. When a volcano erupts, it releases a variety of gases and ash into the atmosphere, including sulfur dioxide, carbon dioxide, and particulate matter. These emissions can have immediate impacts on air quality, altering weather patterns and affecting climate. The particulate matter from volcanic ash can be harmful to human health when inhaled and can also affect ecosystems by depositing on land and water bodies.

In contrast, traffic emissions, industrial waste, and chemical manufacturing are all examples of anthropogenic, or human-made, sources of air pollution. While they contribute significantly to air quality degradation and health risks, they do not fall under natural sources like volcanic eruptions do.