NBC 的报道： 样本测试达标不超过10%
NBC News had a lab test the tap water in two dozen homes in New Orleans, a 300-year-old city with aging infrastructure and many lead pipes. The results, including Bourgeois’, revealed that harmful levels of lead may be much more prevalent in the city than tests currently prescribed by the Environmental Protection Agency show.
Experts said the NBC News investigation bolstered what scientists, including those at the EPA, have known for years — federally mandated tests used across the country to ensure water systems are safe may significantly underestimate lead levels in drinking water. By some estimates, up to 90 million Americans could be drinking from water systems that, if tested more rigorously, would not pass federal muster.
“The flaws in our sampling program have created a false sense of confidence both with the utilities, and the EPA, and consumers in this country that lead in water is a problem of the past,” said Dr. Marc Edwards, the Virginia Tech researcher who helped expose widespread lead contamination in the water in Flint, Michigan. “This is a problem of the present.”
The disaster in Flint brought national attention to lead in water just as the EPA finalizes new regulations, due out in 2017. But it’s unclear if the revisions will include more rigorous testing of drinking water.
New Orleans, which has among the highest blood lead levels of children in the state, is a case in point.
Seven of the 24 homes tested by NBC News, or nearly 30 percent, had at least one sample that exceeded 10 parts per billion, the maximum acceptable level set by the World Health Organization. Three of those seven homes tested over 15 ppb, the point at which the EPA says that action must be taken.
The tests indicate lead may be more common than shown in the city’s tests. In 2013, when the New Orleans water board conducted its last round of federally-mandated lead testing, only one of the 53 homes tested exceeded the EPA threshold. Under EPA guidelines, no more than 10 percent of all samples can exceed the threshold. New Orleans passed the monitoring with flying colors.