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Text 5. Coal and the Environment



As the effects of pollution became more noticeable, Americans decided it was time to balance the needs of industry and the environment.

Over a century ago, concern for the environment was not at the forefront of public attention. For years, smokestacks from electrical and industrial plants emitted pollutants into the air. Coal mining left some land areas barren and destroyed. Automobiles, coming on strong after World War II, contributed noxious gases to the air.

The Clean Air Act and the Clean Water Act require industries to reduce pollutants released into the air and the water. Laws also require companies to reclaim the land damaged by surface mining. Progress has been made toward cleaning and preserving the environment.

The coal industry’s largest environmental challenge today is removing organic sulfur, a substance that is chemically bound to coal. All fossil fuels, such as coal, petroleum, and natural gas, contain sulfur.

When these fuels are burned, the organic sulfur is released and combines with oxygen to form sulfur dioxide. Sulfur dioxide is an invisible gas that has been shown to have adverse effects on air quality.

The coal industry is working to solve this problem. One method uses devices called scrubbers to remove the sulfur in coal smoke. Scrubbers are installed at coal-fired electric and industrial plants where a water and limestone mixture reacts with sulfur dioxide to form sludge. Scrubbers eliminate up to 98 percent of the sulfur dioxide. Utilities that burn coal spend millions of dollars to install these scrubbers.

The coal industry has made significant improvements in reducing sulfur emissions. Since 1989, coal-fired plants in the United States have lowered sulfur dioxide emissions per ton by a fourth and have increased efficiency significantly.

Coal plants also recycle millions of tons of fly ash (a coal by-product) into useful products such as road building materials, cement additives and, in some cases, pellets to be used in rebuilding oyster beds.

Carbon dioxide is released when coal is burned, just as it is released from the human body during respiration. Carbon dioxide combines with other gases, such as those emitted from automobiles, to form a shield that allows the sun’s light through the atmosphere, but doesn’t let the heat that is produced out of the atmosphere. This phenomenon is called the greenhouse effect. Without this greenhouse effect, the earth would be too cold to support life.

There is concern that human activities are causing major changes in greenhouse gas levels in the earth’s atmosphere that are responsible for a change in the earth’s climate.

 

Words to know

1. forefront

2. smokestacks

3. barren

4. noxious

5. reclaim

6. adverse

7. scrubbers

8. sludge

9. fly ash

10. pellets

11. respiration

 

Exercise 1. Explain the meaning of the following words and word combinations:

greenhouse effect, additive, by-product, fossil fuel, to be chemically bound to coal

 







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