WATER POLLUTION AND ENVIRONMENT

Soheila Khoshnevis Yazdi, Anahita Fashandi, Islamic Azad University, Tehran, Iran

Abstract

Any physical, biological or chemical change in water quality that adversely affects living organisms or makes the water unsuitable for desired uses.Water pollution refers to harmful substances released into surface or ground water, either directly or indirectly. Hydrologic impacts refer to changes in surface (streams and rivers) and groundwater flows. Pollution can be defined in several ways.
Water is a unique substance, because it can naturally renew and cleanse itself, by allowing pollutants to settle out (through the process of sedimentation) or break down, or by diluting the pollutants to a point where they are not in harmful concentrations. However, this natural process takes time, and is difficult when excessive quantities of harmful contaminants are added to the water. And humans are using more and more materials that are polluting the water sources that we drink from. Beach closures are becoming increasingly common.