AirChapter 12

Air Pollution – any harmful substance put into the air◦Can come from human sources or natural sources

◦Natural sources include volcanoes, forest fires, burping lakes

Section 1 – Air Pollution

Primary pollutant – pollutant put into the air directly by human activity

Secondary pollutant – forms when primary pollutants react with other primary pollutants or with naturally occurring substances (ex. Acid rain)

Most air pollution produced by humans comes from transportation and industry.

Transportation – almost 1/3 of air pollution comes from burning gasoline in motor vehicles

Industry – many industries burn fossil fuels to produce energy

Passed in 1970, amended in 1990◦Gives the Environmental Protection Agency (EPA) the authority to regulate motor vehicle emissions California has the strictest laws

1) removed lead from gasoline2) Mandated the use of the catalytic converter (p. 328 Figure 3)

Clean Air Act

Controlling Vehicle Emissions

The Clean Air Act requires industries to use pollution control devices◦Ex: Scrubbers and electrostatic precipitators

◦Scrubbers work by spraying gases with water, which removes many pollutants (page 329 Figure 5)

Regulating Air Pollution From Industry

Smog – when air pollution hangs over urban areas and reduces visibility (p. 330 Figure 6)

Temperature inversion – when a layer of cold air is trapped by a layer of warm air. This traps air pollutants and is more likely to occur in a valley (p. 330 Figure 7)

Smog

Temperature Inversions

Make sure that you copy the “Primary Pollutants” Chart from p. 326 into your notes!

Effects of Air Pollution

Short Term – occurs when symptoms come on quickly and usually go away within a few hours or days

Section 2Air, Noise, and Light Pollution

HeadacheNauseaDizziness Irritation of eyes, nose, and throatCoughingTightness in the chestUpper respiratory infection

Examples of short term effects

Long Term – these symptoms occur after being exposed to air pollution for a long period of time (Chronic exposure)◦These symptoms DO NOT EVER go

away.

Examples of Long Term Effects• Emphysema• Lung Cancer• Heart Disease

Indoor Air Pollution – when the quality of air inside a building is worse than the air outside◦Because people spend more time inside

than outside, indoor air pollution affects human health more than outdoor air pollution

◦This is more of a problem in buildings that are tightly sealed and well-insulated

Indoor Air Pollution

New paint Building materials New carpets Certain types of furniture – (pressed wood)

“ready-to-assemble” furniture Tobacco smoke Cleaning materials Gasoline Carbon monoxide Radon (radioactive gas given off by granite)

Examples of indoor pollutants

Indoor Air Pollution

If a building has very poor air quality and contains 1 or more of these pollutants, people who spend time in the building can develop a condition called “sick-building syndrome”

In order to have sick-building syndrome, your symptoms must go away when you leave the building and return the next time you enter it.

Sick-Building Syndrome

How to stop indoor air pollution:

1. Identify and remove the source

2. Add ventilation to the building

Asbestos – is several minerals that form long, thin fibers which are very strong and fire resistant◦Asbestos was used in many building

materials

◦If the asbestos fibers break off and become airborne (friable), they can be inhaled and damage the lungs

3 Major Diseases Caused by Asbestos

1. Asbestosis – asbestos fibers in the lungs

2. Mesothelioma – cancer of the chest lining

3. Lung cancer

Radon – colorless, odorless gas that seeps into homes through cracks in the foundation or basement◦Radon is radioactive◦Radon is the second leading cause of lung cancer

◦If the radon levels are high, you must:

1. Seal the cracks and holes in basement/foundation

2. Install ventilation systems

Noise pollution – any loud, unwanted sound◦Can cause damage to hearing and actually destroys cells in your ears

◦Sound at 120 decibels is at the threshold of pain See table 2 on page 334

Noise Pollution

Light pollution – blocks our view of the night time sky◦Does not present a direct hazard to human health

◦More important environmental concern is energy waste

Acid precipitation – rain, snow, sleet, or hail that contains a high concentration of acids◦Caused by the burning of fossil fuels which releases nitrogen oxides and sulfur oxides

◦These chemicals mix with water from the atmosphere and form nitric and sulfuric acid Acid precipitation has a pH of less than 5.0

Section 3 – Acid Precipitation

3 major areas:1) causes a drop in the pH of soil and water acidification

This causes nutrients to get dissolved and washed away

Causes aluminum and other toxic metals to be released

It can clog the openings on the surface of plants

Effects of Acid Rain

2) It can kill fish and other aquatic animals

Acid shock – sudden influx of acidic water that occurs when acid snow melts

3) Effects on humans:• Can cause toxic metals to be released into the

environment• Can cause respiratory problems in children• Dissolves the calcium carbonate in many

building materials

Major problem – pollutants released in one area may fall to the ground hundreds or thousands of miles away

Canada-US Air Quality Agreement (1991)◦Both countries agreed to lower their use

of chemicals that cause acid precipitation

Controlling Acid Precipitation