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Ozone Depletion & Water Pollution. Unit 7-1 Notes Mr. Hefti – Pulaski Biology. Ozone Depletion ► What is it?. Thinning of ozone layer Shield of gases 20-50 km above Earth’s surface that absorb UV radiation from sunlight. OD ► What causes it?.
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Ozone Depletion & Water Pollution Unit 7-1 Notes Mr. Hefti – Pulaski Biology
Ozone Depletion ►What is it? • Thinning of ozone layer • Shield of gases 20-50 km above Earth’s surface that absorb UV radiation from sunlight
OD ►What causes it? • CFCs (chlorofluorocarbons) break apart ozone molecules • CFCs were formerly used to make: • Foam • Coolants • Propellants for aerosol cans
OD ► Why is it bad? • UV exposure causes: • Sunburns • Skin cancer • Damage to eyes • Disrupted growth patterns of producers in food webs • Genetic mutations
OD ► What can be done about it? • Ban CFCs [worldwide]
Water Pollution ► What is it? • Contamination to: • Streams • Lakes • Underground water (aquifers) • Bays • Oceans • All organisms require water
WP ► What causes it? • Major water pollutant categories: • Chemical • Biological • Physical materials • Thermal
WP ► Why is it bad? • Survival impossible in presence of toxic chemicals or harmful microorganisms • Polluted water causes people to become ill or develop defects
WP ► What can be done about it? • Clean Water Act (1972) – outstanding legislation • Sewage treatment • Discourage careless dumping through fines • Limit erosion