Clean Air Primer

Pollutants Add Up To Smog

Smoggy Los Angeles
O₃, CO, NO₂, and C_xH_yO₃NO₂, & PM collect close to the ground in the air we breathe.

Step by Step...
Description of the stages of the chemical reactions that create smog.

Did You Know...
Catalytic converters reduce the levels of nitrogen oxides and unburned hydrocarbons. The hydrocarbons and carbon monoxide are oxidized to carbon dioxide and water and the nitrogen oxides are reduced to nitrogen.

he familiar smog hanging over our cities today is created mainly by the photochemical action of sunlight on pollutants in the exhaust from cars and trucks as well as emissions from industry, businesses, and household products. These pollutants, nitrogen oxide (NOx), carbon monoxide (CO), and unburned hydrocarbons or volatile organic compounds (VOCs) are leftover from the incomplete combustion (burning) of gasoline and other fossil fuels. There are other pollutants smoke (particulates) and other harmful gases.

Source
A series of chemical reactions are set into motion that create photochemical smog:

Shockwave animation of the basic photochemical reaction

Not only does ozone build up quickly, but in other complex photochemical reactions noxious products are created like peroxyacyl nitrates or PANs (C_xH_yO₃NO₂).

Nitrogen dioxide, ozone, PANs and carbon monoxide are all extremely toxic.

How It Hurts
Criteria pollutants add up to smog, bringing their collective damage to us, our environment and our economy.

Back to Ozone In Depth