Chapter 12 Air

12-1 Causes of Air Pollution Clean air = mostly nitrogen and oxygen gases Air pollution is harmful substances in the form of liquids, solids or gases Primary pollutants are put into the air by human activity Secondary pollutants are formed when primary pollutants react with normal air components such as water vapor

Sources Carbon Monoxide: vehicles Nitrogen Oxide: vehicles, power plants Sulfur Dioxide: burning of coal/oil Volatile organic compounds: vehicles, gas station spillage, household products Particulates: Fine: vehicles, power plants Coarse: cement, mining, wood-burning, fields, roads

Although air pollution is worse today because of modern industry, it has been a problem for thousands of years

Clean Air Act of 1970 EPA has the authority to regulate vehicle emissions in the US 90% of lead pollution reduced when gasoline became unleaded Catalytic converters filter pollutants Industries must use air scrubbers (pg. 307) Electrostatic precipitators clean smoke stacks

Motor Vehicle Emissions 1/3 of all air pollution is from vehicles 1990 California Air Resources Board established the zero emission vehicle (ZEV) program By 2016 16% of vehicles in California must be ZEVs Electric, advanced battery, hydrogen fuel vehicles will qualify Hybrids are partial ZEVs

Industrial Air Pollution Power plants burn fossil fuels releasing: 2/3 of all sulfur dioxide 1/3 of all nitrogen oxides VOCs Other industries producing VOCs: Dry cleaning Oil refineries Chemical manufacturing plants Auto repair shops Furniture refinishers

Smog Pollution hanging over urban areas that mixes with sunlight and ozone

Temperature Inversions Air above is cooler than air below which traps pollutants that are normally circulated out

12-2 Air, Noise & Light Pollution

Short Term Effects Headache Nausea Eye, nose, throat irritation Coughing Upper respiratory infections Pneumonia Aggravates Asthma/Emphysema

Long Term Effects Emphysema Lung cancer Heart disease

Indoor Air Pollution Sick-building syndrome – Buildings with very poor air quality due to: Plastics Paints New carpeting/furniture Building materials Common in tightly sealed buildings

Radon Colorless, tasteless, odorless Produced by the decay of uranium Seeps through the foundations of homes 2nd leading cause of lung cancer in the US

Asbestos Used as insulator/fire retardant Banned in the early 70’s Asbestos fibers can cut and scar the lungs Causes serious illness and death

Noise Pollution May cause health problems too! Hearing loss High blood pressure Stress Decibels (dB) – measures sound intensity See chart on page 312

Light Pollution Doesn’t pose health threat Negatively affects the environment Diminishes view of night sky Energy waste

12-3 Acid Precipitation

Causes Sulfur oxides and nitrogen oxides are released from the burning of fossil fuels These combine with water in the atmosphere which falls as acid rain Adversely affects ecosystems

pH Scale that determines how acidic or basic a substance is See page 314 7 is neutral Lower numbers (below 7) are higher acidity Higher numbers (above 7) are higher basicity

Affects on Soil/Plants Increase soil acidity Decreases nutrients Increases toxic metals that are absorbed into roots Clogs surface openings on plants

Affects on Aquatic Ecosystems Acid shock may be fatal for fish and other organisms Affects reproduction Acidified lakes are treated with limestone to raise the pH

Affects on Humans Toxic metals from soil into food chain Increase in respiratory problems Dissolves building materials

International Pollutants released in one area fall as acid precipitation in another area International agreements are needed to control the problem