Pollution

• Author: Jeffrey Lehman, Shirelle Phelps

Page 25

The contamination of the air, water, or earth by harmful or potentially harmful substances.

The U.S. environmental movement in the 1960s emerged from concerns that air, water, and soil were being polluted by harmful chemicals and other toxic substances. During the industrial revolution of the nineteenth century, the mass production of goods created harmful wastes, much of which was dumped into rivers and streams. The twentieth century saw the popular acceptance of the automobile and the internal combustion engine, which led to the pollution of the air. Rapidly expanding urban centers began to use rivers and lakes as repositories for sewage.

Land pollution involves the depositing of solid wastes that are useless, unwanted, or hazardous. Types of solid waste include garbage, rubbish, ashes, sewage-treatment solids, industrial wastes, mining wastes, and agricultural wastes. Most solid waste is buried in sanitary landfills. A small percentage of municipalities incinerate their refuse, while composting is rarely employed.

Modern landfills attempt to minimize pollution of surface and groundwater. They are now located in areas that will not flood and that have the proper type of soil. Solid wastes are compacted in the landfill and are vented to eliminate the buildup of dangerous gases...