Which ions are second only to particulate matter from smoke in terms of damage caused to human health by air pollutants?

Sulfur ions are particularly harmful to human health primarily because of their role in the formation of sulfur dioxide (SO2) when fossil fuels are burned. Once released into the atmosphere, sulfur dioxide can react with other compounds to form fine particulate matter and sulfuric acid, which can lead to respiratory issues, aggravate cardiovascular diseases, and contribute to acid rain.

High levels of sulfur pollution can be detrimental not only to health but also to the environment, influencing ecosystems and water sources. The significance of sulfur as a pollutant stems from its widespread presence in industrial emissions and the consequent exposure to humans, especially in urban areas. This positioning as a dangerous air pollutant places sulfur ions second only to particulate matter from smoke regarding the damage they can inflict on human health.