Wednesday, August 31, 2016

Is DOE using the right protocols to test for lead? And new evidence about its devastating impact


Update  9/2/16:  NY Times reports that NYC will change their method of lead testing in school water but unclear if this methodology would match best practices: "In the future the city would try to conduct as many tests as possible while school was in session, and on mornings other than Mondays, and that for these tests it would abandon the pre-stagnation flushing step. But she said the city would continue doing the pre-stagnation flushing when it was necessary to collect samples on Monday mornings or over school holidays."  More here.

Update 9/1/16:  WNYC/Schoolbook reported today that the city said it will stick to its discredited method of testing for lead in school water, even though it doesn't follow EPA protocols and the foremost expert on lead contamination said their results were essentially meaningless.  The reporter, Beth Fertig, also linked to this blog for the discussion below of how even very low levels of lead in blood have been linked to lower test scores and higher rates of special needs.  For the full list of NYC schools tested in July with the discredited method, and the results, including which 509 schools were identified with high levels of lead, see here.

 Today, Kate Taylor of the NY Times reported that the method that NYC Department of Education has used to test lead in school water by flushing the pipes extensively beforehand is seen as illegitimate by the same scientific experts at Virginia Tech who first revealed the crisis in Flint:

“The results should be thrown into the garbage, and the city should start over,” said Marc Edwards, a civil engineering professor at Virginia Tech who helped uncover dangerously high lead levels in the water in Flint, Mich., touching off scrutiny of drinking water across the country.
  

Yanna Lambrinidou, an anthropologist who has worked with Dr. Edwards to expose lead contamination in water in Washington, D.C., and elsewhere, and an affiliate faculty member at Virginia Tech’s Department of Science and Technology in Society, said in an email that New York City’s schools “may have just broken the national record for flawed testing.”
 

I never understood why the DOE’s procedure using pre-flushing would be an accurate way to detect how much lead there may be in the water that settles into pipes and water fountains at the point when schoolchildren actually drank from them.

A few months ago, after the Flint scandal emerged, DOE said they had already tested the water in all public schools built before 1986, and that this was all that was necessary, because that  year the use of lead piping was banned.  They added that “the vast majority are confirmed negative.”

Yet then it turned out that in the majority of cases, even for the schools built before 1986, this testing had not happened for more than ten years! 

DOE initially said they would only retest the water at these older schools, even though many experts including Marc Edwards advised that all schools should be tested regularly because of the use of lead in soldering in water fountains past that date.   

Subsequently, the DOE switched positions, and when they finally tested all 1500 schools, the results were not encouraging: a startling 509 schools were found to have elevated levels on the first or second draw, even after the flushing exercise noted above:

But the amounts did not indicate potential harm to students, Schools Chancellor Carmen Fariña said. “Families can rest assured that water in school buildings is of the highest quality and is safe for students and staff to drink,” Fariña said. “Schools are following the aggressive flushing and remediation protocols that the Department of Education has had in place for years. We continue to update families and school staff throughout the process.

More specifically, to address these problems, the DOE wrote:

For those buildings that had even one outlet with results above recommended levels (even if the test was in the past), we have been implementing a protocol, approved by DOHMH and based on EPA guidance, involving a combination of weekly flushing, equipment replacement and more, to ensure the safety of students and faculty. Flushing has been shown to be highly effective in removing lead from water because (a) flushing builds up the protective coating on plumbing pipes and (b) flushing moves old water out of the system and brings in fresh water. 

Yet the DOE did not make clear in which schools flushing would be used alone and in which would the equipment be replaced. I asked these same questions in my blog back in July, when the widespread nature of the problem was first revealed.

And while  the DOE now says they will now retest all schools every five years, Marc Edwards, the same VA Tech expert, has  recommended that schools test their water annually,

Coincidentally, yesterday I was reading two articles that I have not seen widely reported, revealing that  higher lead levels of poor and black children may be a major contributor to the test score gap.  These studies also suggest that there is no safe level of lead either in the blood or presumably in drinking water.  As the NY Times reported today:

Lead poisoning among children has declined in New York City since 2005, according to a 2015 report by the Department of Health and Mental Hygiene. In 2014, 840 children under 6 were newly identified with blood lead levels of at least 10 micrograms per deciliter — a level the C.D.C. used to use as its “level of concern” — down from 2,705 children in 2005. (The C.D.C. revised its guidelines in 2012, saying that five micrograms of lead per deciliter of blood should be of concern.)

Yet even below five micrograms, there seems to be an impact on student achievement.

In a recent NBER paper called Do Low Levels of Blood Lead Reduce Children's Future Test Scores?, written by economists at Brown and Princeton, researchers found that by looking at the blood lead levels of preschool Rhode Island children born between 1997 and 2005 and their subsequent third grade test scores, the higher their blood lead level (BLL) the lower their test scores tended to be: "Using these data, we show that reductions of lead from even historically low levels have significant positive effects on children's reading test scores in third grade.”

The students’ mean BLL was 3.1, “which is well below the CDCs threshold for medical intervention of 5 micrograms per deciliter. African American and Hispanic children both have higher mean levels, as do children who always receive free school lunch (4.2, 3.6, and 3.9, respectively.)

The researchers found that “a one unit decrease in average blood lead levels reduces the probability of being substantially below proficient in reading by 3.1 percentage points (on a baseline of 12 percent). Moreover, poor and minority children are more likely to be exposed to lead, suggesting that lead poisoning may be one of the causes of continuing gaps in test scores between disadvantaged and other children…”.

In an earlier paper, called "Lead Exposure and Racial Disparities in Test Scores," these same researchers concluded that the the decline in racial disparities in lead explains between 37 and 76% of the decline in racial disparities in test scores over the past decade in Rhode Island.  Yet significant disparities remain, in both blood lead levels and test scores:

Among Rhode Island children born between 1997 and 2004, African American children have average lead levels of 4.8 compared with 4.2 for Hispanic children and 3.1 for white children. Likewise, children of less educated mothers have lead levels of 4.6 on average, compared to children with more educated mothers whose lead levels are 3.2. The same patterns are true if we classify children by whether they are eligible for free lunch or not (4.1 vs. 2.7), their mothers are single or married (4.2 vs. 3.0) and whether they live in a poor neighborhood ….

Not only are African American children more likely to be exposed, but they may also suffer more harm from a given level of exposure. For example, good nutrition and cognitive stimulation may be protective against the negative effects of lead poisoning, and African American children may be less likely to enjoy these protective factors (Environmental Protection Agency, 2015).

Indeed, according to the cited EPA document, "Children with empty stomachs absorb more lead than children with full stomachs. Provide your child with four to six small meals during the day."

The researchers also concluded that there was no threshold at which a child's blood lead levels did not predict his later test scores or the probability of having an IEP:

Children with an average BLL of 0 score nearly 5 points higher (42% of a standard deviation) than those with BLLs of 5. Similar patterns are observed for math test scores, as well as for the probability of having an IEP which increases from 20 percent for those with 0 BLLs, to 27 percent for those with a BLL of 5 and over 30 percent for those with a BLL of 10.

See these startling graphs, showing that the slope of the line signifying the decline in test scores and the likelihood of having an IEP was as sharp, if not sharper, between O and 5 BLL (supposedly safe levels) as between 5 and 10 BLL (dangerous levels, according to the EPA).
 


Aizer, Currie, Simon, and Vivier, “Lead Exposure and Racial Disparities in Test Scores,” Feb. 7, 2015.
 

So what will the city do now that their methodology for testing lead in schools has been denounced by perhaps the nation’s foremost authority? According to the NY Times,

On Monday, a spokeswoman for Mayor Bill de Blasio, Freddi Goldstein, initially said that while the city believed its testing procedures were sound, “out of an abundance of caution” it would abandon pre-stagnation flushing when it began retesting schools in the fall. A short time later, she rescinded that statement and said the flushing would continue.

This unfortunate dithering follows from an earlier audit, showing that the city Health Department had falsified records at many day care centers to show that they had been tested for lead when they had not.

One would hope that whatever decision is finally made by the Mayor about how to test and remediate for lead in school drinking water, it is made with input from independent experts and with the Precautionary Principle in mind:

"When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context the proponent of an activity, rather than the public, should bear the burden of proof. The process of applying the precautionary principle must be open, informed and democratic and must include potentially affected parties. It must also involve an examination of the full range of alternatives…." - Wingspread Statement on the Precautionary Principle, Jan. 1998

No comments:

Post a Comment