Which of the following is a natural cause of air pollution?
Volcanic eruption
Air is said to be polluted when there is any change in the normal amount of any of the components of air or when foreign substances mix with air. There are many factors which cause air pollution like burning of woods and fossil fuels, smoke from industries, vehicles, burning of plastics and other wastes, etc. Looking at these factors we can say that air pollution is mainly caused by human activities. But there are natural causes of air pollution also. A volcanic eruption is a natural cause of air pollution.