There Is More Than One Type of Air Pollution
Air pollution, as a term, can include everything that diminishes air quality. Along with invisible gases, there can be solid particles (such as lead and volatile organic compounds, also known as VOCs) and droplets of liquids in the air.
Usually, it’s the particles and droplets that lead to the most serious health problems. Together, they form particulate matter (PM), a pollutant the Environmental Protection Agency (EPA) regulates.
However, nitrogen dioxide (NO2), an incredibly reactive gas,is also a concern. It can lead to respiratory problems, including conditions that can be fatal. Ozone is also a lung irritant.