5.7 URBAN AIR POLLUTION

Beijing, China

Tropospheric ozone  Tropospheric ozone (ground level ozone) = bad ozone (not protective) as a result of human activity  Sources:  Burning of fossil fuels  hydrocarbons and Nitric oxides  sunlight and NO 2  formation of 0 3  Problems:  Ozone absorbed by plant leaves degrades chlorophyll so productivity is reduced  Damages crops, forests  Degrades many textiles and rubbers (think of an old rubber band!)

Damage from ozone

Photochemical smog  Smog is often seen as a brown haze above a large city  Sources:  Mixture of ~ 100 primary and secondary pollutants (ozone, gaseous hydrocarbon)  Largely a product of fossil fuel use in combination with sunlight (photochemical reaction) Problems: Toxic gas (lead to breathing difficulties and health problems)

Smog Pollution in LA

Pollution management strategies  Read the information about Milwaukee’s air pollution  Use the replace, regulate and restore model on page 282 to evaluate air pollution and develop a management plan