Primary pollutants - emitted directly from identifiable sources.
Secondary pollutants - form in the atmosphere when reactions take place among primary pollutants.
Cars, for example, are sources of primary pollutants. They emit carbon monoxide which is one of the biggest contributors (by weight) to air pollution. Though these statistics are horrifying, secondary pollutants can be more harmful and severe to human health than primary pollutants.
Smog is an example of a secondary pollutant. Like air, smog is composed of many different substances including those listed below:
Secondary pollutants - form in the atmosphere when reactions take place among primary pollutants.
Cars, for example, are sources of primary pollutants. They emit carbon monoxide which is one of the biggest contributors (by weight) to air pollution. Though these statistics are horrifying, secondary pollutants can be more harmful and severe to human health than primary pollutants.
Smog is an example of a secondary pollutant. Like air, smog is composed of many different substances including those listed below:
In another example, sulfur dioxide, a primary pollutant, combines with the oxygen already in the air to produce sulfur trioxide. Sulfur trioxide, when mixed with water creates acid rain.