Pollution

Environmental pollution is any discharge of material or energy into water, land, or air that causes or may cause acute (short-term) or chronic (long-term) detriment to the Earth's ecological balance or that lowers the quality of life. Pollutants may cause primary damage, with direct identifiable impact on the environment, or secondary damage in the form of minor perturbations in the delicate balance of the biological food web that are detectable only over long time periods ranging from months to decades.
Until recently, environmental pollution problems have been local and minor because of the earth's own ability to absorb and purify minor quantities of pollutans. The industrialization of society, the introduction of motorized vehicle, and the explosion of the human population of goods and services. 
Coupled with this growth has been a tremendous increase in waste by products. The indiscriminate discharge of untreated industrial and domestic wastes into waterways, the spewing of thousands of tons of particulates and airbone gases into atmosphere, the "throwaway" attitude toward solid wastes, and the use of newly developed chemicals without considering the consequences have resulted in major environmental disasters, such as the formation of smog in the Los Angeles region since the1940s and the pollution of large areas of the Mediterranean Sea. Technology has began to solve some pollution problems, and public awarness of the extent of pollution may eventually force governments to undertake more effective environmental planning and adopt more effective antipollution measures than those currently in use.