One of these THMs is chloroform, a suspected cancer-causing agent. At low levels, reduced birth weight and premature birth, delayed mental and physical development, and impaired mental abilities in children in general, may result. At high levels of exposure, anemia, kidney damage, and mental retardation can occur. Waterborne radon released into the air from showers, washing machines, etc. Can be inhaled and increase the risk of lung cancer.
Many pesticides are toxic and are associated with a variety of health problems.
Even if your drinking water looks, tastes, and smells good, chances are you can't tell if the water you depend on may contain one or more contaminants. The U.S. Geological Survey has pinpointed sources of contamination in every state. Even bottled water isn't necessarily without contamination. Some bottled water isn't always regularly monitored. In 1990, a bottled water survey by the Suffolk County, New York, health department tested bottled water sold in the county and found that 9 of 88 brands tested did not meet state and federal drinking water standards.