Lead Tests in NYC Schools Water May Underestimate RiskSep 6, 2016
The way lead testing was done in New York City school buildings is drawing criticism, with some saying that the method could have underestimated the risk of lead contamination in the drinking water. The results of the tests were announced in July, with officials stating that fewer than 1 percent of all samples taken from over 1,500 schools exceeded guidelines set by the Environmental Protection Agency. Parents were told that the drinking water was safe for their children.
However, a review of the testing suggests that the results may not be accurate, the New York Times reports. The city engaged in a practice known as pre-stagnation flushing, where they turned on every water outlet for two hours the night before the samples were taken. Flushing removes most soluble lead and lead particles from pipes, and lowers the levels of lead temporarily. Marc Edwards, a civil engineering professor at Virginia Tech, said to NYT, "The results should be thrown into the garbage, and the city should start over," Edwards helped identify the dangerously high levels of lead in Flint, Michigan, which triggered concerns about drinking water across the country.
In February, the EPA, said pre-stagnation flushing should not be conducted when sampling lead in homes. The agency stated that the practice "may potentially lower the lead levels as compared to when it is not practiced." School drinking water is not under the jurisdiction of the EPA. However, EPA voluntary guidelines do advise against flushing. Schools should mimic normal consumption patterns when taking samples, the agency recommends.
The testing was also criticized by Yanna Lambrinidou, an anthropologist and an affiliate faculty member at Virginia Tech's Department of Science and Technology in Society who has worked with Dr. Edwards to identify lead contamination. She commented to NYT that the NYC schools "may have just broken the national record for flawed testing."
"Flushing is inappropriate any time you want to assess lead concentrations coming out of individual taps," Dr. Lambrinidou told NYT in an email. "Unless N.Y.C. schools flush every drinking water tap every evening for 2 hours routinely, their sampling technique is both unreliable and scientifically and morally indefensible,".
The EPA's "action level" for lead in municipal water systems is 15 parts per billion. Among the 1,520 school buildings, 510 had at least one outlet where the first sample exceeded this limit. In 153 buildings, there was at least one outlet where the second sample exceeded the cutoff. In eight buildings, at least one outlet had first and second samples exceeding 500 parts per billion. Lead exposure is particularly harmful in children, leading to developmental delays.