The U.S. Environmental Protection
Agency (EPA) tracks 6 major air pollutants that cause major health effects:
- Ground-level ozone
- Nitrogen dioxide
- Sulfur dioxide
- Carbon monoxide
- Microscopic particles called particulate matte
Both the outside air and the air in your home or workplace can have these
pollutants. The amount of pollutant in the air and the length of time you are exposed to
it determine how the pollutant will affect you.
When you breathe in gases such as
carbon monoxide or nitrogen dioxide, the cells that line the airways to the lungs absorb
them. Once taken in, the gases can pass into your blood and travel to your internal
organs. There they can cause damage. If the pollution isn't absorbed into the blood,
damage can still be done to the lungs.
Large particles in the air are
filtered out by the small hairs (cilia) that line your respiratory tract. But smaller
particles reach your airways and lungs. Particles of all sizes also land on crops and in
water. Over time they are eaten by humans, and by animals that humans eat.