A change in the process to disinfect water in the District of Columbia led to a spike in lead blood levels in many city children, says a report to be published in an upcoming issue of the journal Environmental Science and Technology. Lead exposure in children has been linked to lower IQ tests and behavioral problems.
In 2000, the city switched from a chlorine-based disinfectant system for drinking water to one that uses chloramine, which is created by mixing chlorine with ammonia. The chloramine also altered the water chemistry, causing lead to leach from service lines.
The researchers found that elevated blood levels for toddlers and infants quadrupled between 2000 and 2003.
The study contradicts earlier assurances from the city that the public was not at risk despite the high lead levels in the drinking water.
The researchers also found that certain parts of the city tended to be more at risk than others, but “even in the low-risk neighborhoods” many children probably had elevated blood lead levels” as a result of exposure to lead in drinking water.