A disinfectant used by U.S. water utilities dissolves lead in laboratory experiments. The finding bolsters the notion that the disinfectant, called monochloramine, may be responsible for increased lead in some drinking-water supplies.
Utilities have traditionally disinfected drinking water with chlorine. However, the chemical can react with organic compounds in water, generating by-products that include suspected cancer-causing agents. So, some utilities have switched to monochloramine, a compound of chlorine, nitrogen, and hydrogen.
But with the swap came reports of higher concentrations of lead in some water supplies. For example, Washington, D.C.'s water contained lead levels as high as 48,000 parts per billion (ppb) in 2003, 3 years after the city began using monochloramine. The Environmental Protection Agency limits lead in drinking water to 15 ppb. Sources of lead contamination include corroding pipes and solder.