Perhaps no factor is more useful in the control of disease than the science of sewage disposal. It safeguards a community’s water supply by removing water-carried wastes including microscopic dissolved material, solid matter such as human waste, and harmful chemicals and bacteria. Sewage is generally divided into two classes: domestic, or sanitary, sewage and industrial [...]

1869: Birth of ecology. Most people are unaware that the subdivision of biology called ecology is over a century old. Over the course of its development, ecology has emerged as one of the most significant and studied aspects of biology. Ecology refers to the overall interrelated system of nature and the interdependence of all living [...]

DEFINITION:1 a) the branch of biology that deals with the relations between living organisms and their environment b) the complex of relations between a specific organism and its environment 2 Sociology the study of the relationship and adjustment of human groups to their geographical and social environments. 1869: Birth of ecology. Most people are unaware [...]

HOW DDT KILLED THE ROBINS. Dutch elm disease threatened to destroy most of the majestic elms that once flourished along residential streets. To eliminate the beetles that carry this fungus disease, many communities sprayed their elms with massive doses of DDT. The pesticide stuck to the leaves even after they fell in the autumn. Earthworms [...]

The reasonable use of the Earth’s natural resources water, soil, wildlife, forests, and minerals is a major goal of conservation. Conservation is the preservation and maintenance of the environment to meet human needs for production while insuring that proper consideration is also given to aesthetics and recreation. An effective conservation program results in a continuous [...]

WATER CONSERVATION Polluted water in one part of the world affects water sources everywhere. This happens because water moves through what is called the hydro logic cycle. In the hydro logic cycle 1) water moves into the air and clouds as it evaporates from oceans, lakes, and rivers. 2) the winds that blow around the [...]

Water Pollution Since the beginning of civilization, water has been used to carry away unwanted refuse. Rivers, streams, canals, lakes, and oceans are currently used as receptacles for every imaginable kind of pollution. Water has the capacity to break down or dissolve many materials, especially organic compounds, which decompose during prolonged contact with bacteria and [...]

  Industrial Pollution Efforts to improve the standard of living for humans through the control of nature and the development of new products have also resulted in the pollution, or contamination, of the environment. Much of the world’s air, water, and land is now partially poisoned by chemical wastes. Some places have become uninhabitable. This [...]