Chapter 15 Section 11 What are some global effects of pollution? Objective: Explain how pollution spreads across borders.

A World With No Borders The lines that divide countries on maps do not exist in reality. From space, you see just one world, with large areas of land surrounded by even larger areas of ocean.

A World With No Borders Pollution does not stay in just one place. Fumes from automobiles, homes, and factories are carried by the wind around the globe. Pollutants dumped into rivers gradually make their way into the oceans. Ocean currents carry them around the world.

A World With No Borders Pollution is not just one country’s problem. It is a global problem.

ANALYZE: Why is pollution a global problem?

Acid Rain All rainwater is slightly acidic. Certain gases, such as sulfuric oxide and nitric oxide, can mix with rainwater. This makes the drops more acidic.

Acid Rain These gases are produced by power plants, industries, and motor vehicles. Global winds spread the gases across borders. There they mix with rainwater. Many countries other than the ones producing the gases are affected by acid rain.

Acid Rain Acid rain damages forests. It also collects in lakes and rivers, poisoning fish and water plants. It breaks down rock and mud and releases harmful chemicals into the water.

Acid Rain About 10,000 lakes in Sweden contain so much mercury that the government has discouraged people from eating fish caught there. Some bodies of water contain so much dissolved copper that the hair of persons drinking the water turns green.

2. HYPOTHOSIZE: How does acid rain affect the lives of people?

Radiation In 1986, a poorly designed nuclear reactor in Chernobyl, Ukraine, exploded. The explosion and fires that followed released huge amounts of radiation into the atmosphere. It was the world’s worst nuclear energy accident.

Radiation Thirty people working near the reactor died shortly after the accident. Ten more people died later from thyroid cancer brought on by the accident.

Radiation Winds and water carried radioactive dust around the world. The worst affected areas were near the plant. However, Poland, Hungary, and Sweden were also affected. The dust destroyed rich farmlands, contaminated cow milk, and exposed up to 600,000 people to radiation.

3. IDENTIFY: How is radioactive dust spread around the world?

Ozone Holes Ozone is a special form of oxygen. Ozone is created from oxygen by lightning and ultraviolet (UV) light from the Sun. Most of this ozone ends up in a thin layer about 20 km above the Earth’s surface.

Ozone Holes Ozone is very important to life on Earth because it absorbs most of the UV light coming from the Sun. Large amounts of UV light cause eye damage and skin cancer in humans.

Ozone Holes Some industrial chemicals, such as CFCs, release gases that rise into the upper atmosphere. These gases destroy the ozone layer, creating holes in it. In recent years, satellites have found lower than normal levels of ozone above Earth’s poles, particularly in the South Pole region.

Ozone Holes More ultraviolet light is reaching Earth’s surface than in the past. Many industries have begun using ozone- safe chemicals. However, the damage already done may take decades to repair.

4. EXPLAIN: Why is the chemical known as ozone important to people?

15-11 Classwork CHECKING CONCEPTS Why are various kinds of pollution considered to be a global problem? How does pollution spread around the world? How is acid rain spread?

15-11 Classwork THINKING CRITICALLY 4. INFER: How will population increases affect global pollution? 5. APPLY: What can individuals do to reduce global pollution?