How does Ozone take out Pollutants in the Air
Ozone is produced constantly in the upper atmosphere, and since ozone is heavier than air, it begins to fall earthward. As it falls, it combines with any pollutant it contacts, cleaning the air — nature’s wonderful self-cleaning system. If ozone contacts water vapor as it falls, it forms hydrogen peroxide, a component of rainwater, and the reason why rainwater causes plants to grow better than irrigation.
Ozone is also created by lightning, and the amount produced in an average storm is often triple the allowable limit of .015 PPM as set by the US EPA. This ozone is what gives the air the wonderful fresh smell after a rain, and is of the highest benefit to anyone fortunate enough to be breathing it. Ozone is also created by waterfalls and crashing surf, which accounts for the energetic feeling and calm experienced near these sites.
Closer to the ground in large cities, ozone can be produced via waste or exhaust gases (i.e., from automobiles and factories) and the interaction of nitrogen oxide and sulfur oxides. This ozone can accumulate in smog due to temperature inversions and is a lung and eye irritant.
As we are able to measure O3 very accurately, it is therefore used and quoted as an indicator for environmental pollution, though it does not cause it.