Air Pollution: Solutions and Causes
The Clean Air Act
The Clean Air Act is the main force behind the control of air pollution in the United States. The Act was
originally passed in 1963.
It has four major components.
National Ambient Air Quality Standards-targets at major polluting chemicals
EPA establishes New Source Performance Standards
Specified standards for controlling auto emissions with the aim of reducing various gases by
almost 90%
The law encourages states to develop plans (SIP)
The Clean Air Act was last amended in 1990.
Programs in the 1990 Clean Air Act
Smog and other ‘criteria’ (identified) air pollutants
Regulates them by first developing health-based criteria (science-based guidelines)
SMOG
Smog is primarily made up of ground-level ozone. Ozone can be good or bad depending on where it is
located. Ozone in the stratosphere high above the Eart protects human health and the environment,
but ground-level ozone is the main harmful ingredient in smog.
Ground-level ozone—from many sources, smokestacks, cars, paints and solvents.
The smog forming pollutants literally cook in the sky, and if it’s hot and sunny, smog forms more easily.
Since smog travels across county and state lines, a multistate effort to reduce the area’s smog problem.
Other criteria pollutants: carbon monoxide and particulates
Particulates –soots, dusts, smoke
Restrictions on smaller sources such as wood stoves, agricultural burning and dust from fields and roads.
The rode of the federal government and the role of the states
Under this law, EPA sets limits on how much of a pollutant can be in the air anywhere in the United
States.
Mobile Sources (cars, trucks, buses, off-road vehicles, planes, etc.)
Each of today’s cars produces 60-80% less pollution than cars in the 1960’s.
Despite this progress, most types of air pollution from mobile sources have not improved significantly.
What went wrong?
More people are driving more cares more miles on more trips.
Many people live far from where they work
Buses and trucks, which produce a lot of pollution, haven’t had to clean up their engines and
exhaust systems as much as cars.
Auto Fuel has become more polluting—smog-forming VOC vapors into the air.
VOC-volatile (can easily go into a gas) organic compound
1. Cleaner fuels (5 ways cleaner)
1. Phaseout of lead by January 1, 1996
2. Oxyfuel—gasoline with oxygen added to make the fuel burn more efficiently, thereby
reducing carbon monoxide release
3. All gasolines will have to contain detergents
4. The 1990 Clean Air Act encourages development and sale of alternative fuels such as
alcohols
5. Gas stations install vapor recovery nozzles on gas pumps. These noxxles cut down on vapor
release when you put gas in your car.
2. Cleaner cars (hybrids & electric cars)
3. Inspection and maintenance (I/M) programs
Vehicle inspection and maintenance which makes sure cars are being maintained adequately to
keep pollution emissions low.
4. Acid Rain
Acid snow, acid fog, or mist, acid gas and acid dust can harm your health (2 test questions will
come out of this statement!)
The acid rain that has received the most attention is caused mainly by pollutants from big
coalburning power plants in the Midwest
Large amounts of sulfur dioxide as well as NOx (nitrogen oxides) These are acid chemicals
(Answers the questions of ‘Where does our acid rain come from?)
The sulfur dioxide and nitrogen oxides released from the Midwestern power plants rise high into
the air and are carried by winds toward the East Coast of the US and Canada. (Answers the
question: How does acid rain get here?)
What does acid rain do?
Acid lakes and streams have been found all over the country (Acid rain acidifies our fresh water).
Acid rain has damaged trees
The pollutants that cause acid rain can make the air hazy or foggy (Answers the question: What
makes the air hazy?)
Acid air pollution has been linked to breathing and lung problems
Acid air pollution can eat away stone buildings and statues (There is job in DC for the Federal
Government to clean the monuments from acid rain)
Emission allowances EPA will issue allowances to power plants; allowance is worth one ton of
sulfur dioxide released from the smoke stack.
Repairing the ozone layer (there are not truly holes in the ozone layer)
Scientists have found ‘holes in the ozone layer high above the Earth
Ozone holes aren’t like doughnut holes; they’re not empty spaces in the sky. Ozone holes are
much like the worn-out places in an old sock or sweater. There are still threads covering the worn-out
area, but the fabric can be so thin you can see right through it.
Ozone in the stratosphere serves as a protective shield, filtering out harmful sun rays, including a type of
sunlight called ultraviolet B
Chlorofluorocarbons (CFC’s) then as aerosol propellants: hairsprays, deodorants (all used to be sprays)
Because of concern about possible effects of CFC’s on the ozone layer, in 1978, the US Government
banned CFC’s as propellants in aerosol cans (only in the US)
Where found
1.
2.
3.
4.
Ozone hole was found above Antarctica (South Pole)
Above the Northern half of the Unites States extends over Canada
Into the Arctic regions (the area of the North Pole)
Over Northern Europe
Unfortunately, it will be a long time before we see the ozone layer repaired. Because of the ozonedestroying chemicals already in the stratosphere and those that will arrive within the next few years,
ozone destruction will likely continue for twenty years plus (not deteriorating now—like before)
Ozone = O3 (sub script). When CFC’s and Ozone meet it becomes O2 and O
NOTE holes in the ozone are not caused or connected to Global Warming
CFC’s from car air conditioners are the biggest single source of ozone-destroying chemicals by 1993.