The air we breathe sustains human life on earth; yet today much of the air can contain a form of airborne mercury; courtesy of our power plants that burn coal. The fact you are inhaling airborne heavy metals goes completely unnoticed as you cannot see any of this going on. However the only alert you get is when your health begins to fail.
Air pollution from fuel emissions from cars are known as hydrocarbons, these react with sunlight and nitrous oxides in the air. When this reaction happens ground level smog is created. This smog contributes to the air pollution causing respiratory symptoms, cancers, and eye irritation.
Most of us are exposed to a vast number of toxins on a daily basis, week after week, month after month, year in year out. When this is considered the quantities we are exposed to is huge and the point is that these trace amounts begin to accumulate in the body over time. So the resulting effect on peoples health is dramatic!