Air Air Chapter 2Chapter 2

• Name five primary air pollutants, and give sources for each.

• Name the two major sources of air pollution in urban areas.

• Describe the way in which smog forms.

• Explain the way in which a thermal inversion traps air pollution.

The Air Pollution Problem

• Air is a mixture of gases.– Nitrogen ___% and Oxygen ___% followed by

_______________ of Argon, CO2, and WV.

• Air pollution is the contamination of the atmosphere by wastes from sources such as industrial burning and automobile exhausts.

• Earliest reference to air pollution dates back to ancient Rome.

• All major air pollution disasters have occurred in industrialized areas.

• Substances that pollute the air can be in the form of solids, liquids, or gases.

• Most air pollution is the result of human activities, but some pollutants are natural, including dust, pollen, spores, and sulfur dioxide from volcanic eruptions.

Primary and Secondary Pollutants

• A ______________ is a pollutant that is put ______________________________or natural activity. An example would be soot from smoke.

• .

• A _________________ is a pollutant that _______________________________, natural components in the air, or both. An example would be ground-level ozone.

• Ground level ozone forms when the emission from cars react with the UV rays of the sun and then mix with the oxygen in the atmosphere

Outdoor Pollutants

• Particulates __________________________• ____________________________.

– Ex. Ash, dust, and traces of metals.

• ____________ – compounds of oxygen and another element.– Forms acid when it chemically reacts with water.– Most of the gaseous pollutants come from these

chemicals.• ____________________________– yellow-

brown haze formed when sunlight reacts with pollutants produced by cars.

• _____________________ (CFCs) – compounds of C, Cl, and F once used in refrigerators, air conditioners, aerosol cans, and in the production of polystyrene.

Smog

Smog _______________________________________________________________________________________________________.

Smog results from chemical reactions that involve sunlight, air, automobile exhaust, and ozone.Pollutants released by vehicles and industries are the main causes of smog.

Particulates

Indoor Pollutants

• Improving air circulation can reduce the amount of pollutants in your home.

• The combination of particulates, gases, and other chemicals contained in cigarette smoke makes it the deadliest of all indoor pollutants.

Radon System

Radon – ________________________________.

Short-Term Effects of Air Pollution on Health

• Many of the effects of air pollution are short-term and reversible if their exposure to air pollution decreases.

• For example: headache; nausea; irritation to the eyes, nose and throat; coughing; tightness in the chest; and upper respiratory infections, such as bronchitis and pneumonia.

• Pollution can also make the conditions of asthma and emphysema worse for certain individuals.

Long-Term Health Effects of Air Pollution

• Long-term effects on health that have been linked to air pollution include emphysema, lung cancer, and heart disease.

• Long-term exposure to air pollution may worsen medical conditions suffered by older people and may damage the lungs of children.

Air Pollution and Living Things

• Air pollution has been linked to many health problems.

• Carbon Monoxide (CO) – ___________________ __________________________reducing it from

reaching cells and resulting in stress and death at high levels.

• Cigarette smoking is a factor in causing lung cancer, emphysema, and heart disease.

Asbestos

• _____________ is any of six silicate minerals that form bundles of minute fibers that are heat resistant, flexible, and durable.

• Asbestos is primarily uses as an insulator and as a fire retardant, and it was used extensively in building materials.

• However, for all of its uses, the government banned the use of most ________________

_______________________.

• Asbestos fibers can cut and scar the lungs, causing the disease asbestosis.

• Victims of the disease have more and more difficulty breathing and may eventually die of heart failure.

• Emphysema – a disease in which tiny air sacs in the lungs break down.

• Cancer – a disease in which cells grow abnormally and without restraint.

Other Health Issues

The US loses up to $10 Billion worth of crops each year because of air pollution.Industrial air pollutants can contaminate farmland and grazing areas leading to high levels of lead and zinc.

Global Effects of Air Pollution

• Three major air pollution problems threatening the global environment:– Acid Precipitation– Ozone Depletion– Global Warming

A ___________________________is the atmospheric condition in which warm air traps cooler air near Earth’s surface.The warmer air above keeps the cooler air at the surface from moving upward. So, pollutants are trapped below with the cooler air.If a city is located in a valley, it has a greater chance of experiencing temperature inversions (as seen in LA).

• Acid precipitation _____________________ _____________________________________ _______________________________When fossil fuels are burned, they release oxides of sulfur and nitrogen.

• When these oxides combine with water in the atmosphere they form sulfuric acid and nitric acid, which falls as acid precipitation.

What Causes Acid Precipitation?

Acid Precipitation

• Acid precipitation has become more common in the last 200 years due to increased fossil fuel use.

What Causes Acid Precipitation?

• This acidic water flows over and through the ground, and into lakes, rivers, and streams.

• Acid precipitation can kill living things, and can result in the decline or loss of some local animal and plant populations.

What Causes Acid Precipitation?

• A pH number _________________________ _____________________________________ ___________________________________.

• Each whole number on the scale indicates a tenfold change in acidity.

• A pH of 7 is neutral, a pH of less than 7 is acidic, and a pH of greater than 7 is basic.

• Pure water has a pH of 7.0, while normal precipitation has a pH of about 5.6.

What Causes Acid Precipitation?

• Normal precipitation is slightly acidic because atmospheric carbon dioxide dissolves into the precipitation and forms carbonic acid.

• Precipitation is considered acid precipitation if it has a pH of less than 5.0

• The pH of precipitation in the eastern U.S. and Canada ranges from 4.2 to 4.8, with the most acidic precipitation occurring around Lake Erie and Lake Ontario.

What Causes Acid Precipitation?

Acid Rain

• _______________is the sudden runoff of large amounts of highly acidic water into lakes and streams when snow melts in the spring or when heavy rains follow a drought.

• This phenomenon causes large numbers of fish to die, and affects the reproduction of fish and amphibians that remain. They produce fewer eggs, and those eggs often do not hatch. The offspring that do survive often have birth defects and cannot reproduce.

International Conflict

• One problem in controlling acid precipitation is that pollutants may be released in one geographical area and fall to the ground hundreds of kilometers away.

• For example, much of the acid precipitation that falls in southeastern Canada results from pollution produced in the northeastern United States.

Ozone Depletion

• O3 – Ozone Gas

• Atmospheric ozone helps life on Earth by blocking out UV rays.

• Found in the Stratosphere.

• Corrosive and poisonous gas on Earth’s surface.

Hole in the Sky

• Early 1980’s, scientists discovered a thin area, or hole, in the ozone layer over the South Pole.

• UV radiation can cause sunburn, blindness, and skin cancer as well as severe crop damage.

Causes of Ozone Depletion

• Ozone depletion will continue because CFCs last up to 50,000 years.

• Chlorine and fluorine are the atoms responsible for destroying ozone molecules.

Global Warming

• Light energy enters the atmosphere and is absorbed at the surface. Light energy is changed to heat. Heat energy is radiated back to space in the form of infrared radiation.

The Greenhouse Effect• CO2 is the most significant greenhouse gas emitted in

large quantities by humans.• Greenhouse effect got its name because heat is

trapped.• Ice cores – long cylinders of ice that are drilled and

removed from deep within a sheet of polar ice.• Ways to reduce Greenhouse Gases in the atmosphere:

– Electric Cars

– Solar Power

– Increasing Fuel Efficiency Standards

Effects of Greenhouse Gas Pollution

• During the past 150 years, levels of atmospheric CO2 has increased due to increased fossil fuel use.

• Global Warming – _________________________ __________________________________________ _______________________________

• Some computer models project that Earth’s temperatures will rise by 2 – 4 degrees C.

• Ice Caps will melt, coastal areas will flood, weather patterns will change, salt water will enter freshwater aquifers.

Controlling Air Pollution• _____________________, passed in 1970 and

strengthened in 1990, gives the Environmental Protection Agency (EPA) the authority to regulate vehicle emissions in the United States.

• The EPA required the gradual elimination of lead in gasoline, decreasing lead pollution by more than 90 percent in the United States.

• In addition, ___________________, required in all automobiles, clean exhaust gases of pollutants before pollutants are able to exit the tail pipe.

• The Clean Air Act requires many industries to use __________ or other pollution-control devices.

• Scrubbers remove some of the more harmful substances that would otherwise pollute the air.

• A scrubber is a machine that moves gases through a spray of water that dissolves many pollutants. Ammonia is an example of a pollutant gas that can be removed from the air by a scrubber.

• _____________________are machines used in cement factories and coal-burning power plants to remove dust particles from smokestacks.

• In an electrostatic precipitator, gas containing dust particles is blown through a chamber containing an electrical current.

•An electric charge is transferred to the dust particles, causing them to stick together and to the sides of the chamber.

Natural Air Pollution Controls

• Precipitation is the most effective natural method of removing particulates and aerosols from the air.

• Two ways to remove CO2:– Biological Activity (Photosynthesis and Shell

Formation)– Oceans (Cold temperatures hold more CO2)