Disinfection By-products.

The article presents information on disinfection by-products. Chlorine is the most widely used water disinfectant because of its effectiveness and cost. Research shows that chlorine has side effects. It reacts with organic matter present in water and forms a series of compounds that have been linked to cancer in animals. All living organisms have carbon as an essential element in their cells. When trees shed their leaves, they start decomposing and are ultimately broken down by bacteria into carbon-containing compounds. Similarly, dead animals on land and fish and other aquatic life decompose and disintegrate into compounds that contain carbon as an essential element. Disinfection can produce hundreds of by-products when chlorine reacts with organic matter. In 1979, the U.S. Environmental Protection Agency adopted regulations that established a maximum contaminant level of 0.1 mg/L for total trihalomethane.