Air Pollutant

Air pollutant are of two types: primary and secondary. Primary air pollutants are directly emitted into the atmosphere from natural and human-related sources. Secondary air pollutants are produced within the atmosphere from the interaction of primary polutants. Ozone is a secondary air pollutant. It is formed in a two-step process, within the atmosphere, from the interaction of NO2 (nitrogen dioxide, a primary pollutant), O2( normal atmospheric oxygen), and sunlight.

Atmosphere ozone levels are significantly influenced by meteorological conditions. Concentration levels are usually higher during the summer months, when there is more sunlight than during winter months. High ozone levels can, however, occur during winter months as a result of air stagnation (temperature inversion).

The secondary air pollutant ozone effects the eyes and the mucous membranes of the nose and throat. Its effects are more severe in individuals with chronic lung disease.

[source: Chemical Principles by H. Stephen Stoker]