it is true that LEED Certified green buildings are providing healthier environmental conditions for their occupants. As an example, Low Emitting Materials credit aimed to reduce concentrations of chemical contaminants that can damage air quality, human health, productivity, and the environment. There is a sneaky source of toxic gas that most of us even are not even aware of it. It is our chlorinated municipal water. Chlorine is a used as a disinfectant in municipal water supplies as an effective way to kill the bacteria in our drinking water. Many of us don’t use tap water for drinking purpose but it is assumed some people will drink it at some point. When chlorine is used as a water treatment, it combines with organic matter to form compounds called trihalomethanes, also known as disinfectant byproducts. One of the most common THMs formed is chloroform, which is a known carcinogen. Other THMs formed include the di- and trichloramines formed when chloramine is used as a disinfecting agent. These compounds are toxic when consumed, inhaled, or applied to the skin.Latest research conducted on the health effects of chlorinated water have shown heavy toxicity issues.