What causes air pollution? Air 12-1 and 2

Air Pollution Harmful substances in the air at unhealthy levels Human activities Natural sources

Mexico City

Primary Pollutants Pollutant that is put directly into the air Soot from smoke

Secondary Pollutants Form when primary pollutants react with naturally occurring substances Ground-level ozone – UV light reacts with car emissions

Motor Vehicle Emissions 1/3 of air pollution come from cars EPA required gradual elimination of lead Catalytic converter – required in cars

Catalytic Converter Clean exhaust gases before they are able to leave tailpipe

California Zero-Emissions Vehicle Program Account for ½ of pollution Encourage development of less-polluting vehicles ZEV – electric cars Partial ZEV – hybrids and methanol fuel cells

Industrial Air Pollution Clean Air Act Scrubbers – machine that moves gases through a spray of water that dissolves pollutants

Clean Air Electrostatic precipitators – remove dust particles from smoke stacks Polluted air blown through charged chamber Sticks to sides of chamber Coal –burning power plants and cement factories

Smog Chemical reaction between: Found in urban areas Sunlight Air Car exhaust Ozone Found in urban areas

Temperature Inversions Warm air traps cooler air near Earth’s surface Valley cities

Los Angeles, CA

Health and Air Pollution Short term: Headaches, nausea, irritation of eyes or throat, coughing, infections

Health and Air Pollution Long term: Emphysema, lung cancer, heart disease

Indoor Air Pollution Sick Building Syndrome – health problems caused by indoor pollutants Building materials Paints Carpets Fungus Mold

Radon Gas Colorless, tasteless, odorless Radioactive Radon is an element that is produces by the decay of uranium Found in earth – seeps into foundation 2nd leading cause of lung cancer

Asbestos Strong insulator and fire retardant Mineral in long, thin fibers Found in building materials Banned in 70’s Heart and respiratory disease

Noise Pollution Destroys cells in ear MP3 and iPods Decibels (dB) – sound units

Light Pollution No health effects Environmental effects – diminish view of night sky Energy loss Lights pointed down or low emission lighting