ITHACA, NY – It seemed like we, as a nation, had largely gotten past the issue of lead contamination. We knew where it came from and we seemed to have it, for the most part, under control.
[do_widget id= text-55 ]
As far back as ancient Rome, people knew that lead was bad for you, but for those who are unaware, here’s what the Centers for Disease Control (CDC) says about the dangers of lead:
“No safe blood lead level in children has been identified. Even low levels of lead in blood have been shown to affect IQ, ability to pay attention, and academic achievement. And effects of lead exposure cannot be corrected. The most important step parents, doctors, and others can take is to prevent lead exposure before it occurs.”
Today, most people know to watch out for lead-based paint chips in old houses or toys that children are seemingly all-too-eager to put in the mouths. The issue of lead in our water supplies has gotten comparably less attention — until a few recent events have really brought it to the forefront.
Enfield and Caroline Elementary schools are in the midst of their own leaden water scare. This comes hot on the heels of the ongoing fiasco that is Flint Water Crisis. Plus, on Monday, the Chicago Tribune reported that Chicago might also have failed to warn its residents about lead contamination in their water supply.
It seems that reliance on lead-based piping for our water pipes is returning to haunt us.
That’s not to say that the three events are on an equal scale. The lead numbers found in Enfield in August are scary, with one fixture putting out water that had 640 parts per billion of lead. By comparison, one Flint residents water measured at 13,200 parts per billion. We’ll get into more of what those numbers mean in a moment.
Fear or danger?
At a meeting in Enfield on Monday to discuss the lead contamination issue, it was clear that parents were frustrated, upset and skeptical of the Tompkins County Department of Health’s assertion that there was no risk to their children and that they didn’t need to get them tested for lead poisoning.
I was reminded of something said during the recent discussion of the Enfield wind farm at the Tompkins legislature: the need to draw a line between fear and actual danger. I confess that, at first, that I saw more of the former. When worry turns to anger and is expressed as vitriol it can become easy to write off people’s legitimate concerns.
On one side, you had a panel of medical specialists and on the other you had a lot of angry parents, some of whom seemed to struggle to articulate their concerns about the science behind the issue, or expressed them with such unmasked hostility that it was uncomfortable to witness.
On its face, the school district’s explanation seemed to add up: the testing in August was done improperly. Because the pipes had been sitting unused during summer break and were not flushed with water before testing, more lead than normal had leached into the water, causing an anomalous reading. A second reading in January indicated levels more in line with what had been observed in the past and so no immediate action was taken.
ICSD Chief Administrative Officer offered apologies for the district’s failure to notify parents in a timely fashion, but maintained that, per the Health Department’s guidelines, there was no safety risk. We’re going to have to dig a little deeper to find the truth of that statement.
Lead, by the numbers
Terms like “parts per billion” and “micrograms per liter” get thrown around when discussing lead in the water. What do these terms actually mean on a practical level?
First of all, it’s important to note that parts per billion (ppb) and micrograms per liter (µg/L) are equivalent measurements. Simply put, they are measurement of how much lead residue is in a source of water.
Micrograms per deciliter (µg/dL) is slightly different — this is the measurement used to determine contamination levels in the blood.
Here are some key numbers to understand:
- 15 ppb of lead in water: This number is considered the “action level” at which water is potentially unsafe to drink. Water suppliers are required to take action to reduce lead levels if they reach this level, and to inform anyone using their water if it cannot be immediately remedied. This number was established by the EPA in 1991.
- 10 µg/dL in blood: As described by the Centers for Disease Control (CDC), this number used to be the threshold for “level of concern,” the point at which doctors were required to inform parents of the result and begin to take steps to prevent additional lead exposure. In 2014, the CDC has revised their guidelines and now regards 10 µg/dL as “a reference value to identify children who have been exposed to lead and who require case management.”
- 5 µg/dL in blood: Per the CDC: “Experts now use a reference level of 5 micrograms per deciliter to identify children with blood lead levels that are much higher than most children’s levels. This new level is based on the U.S. population of children ages 1-5 years who are in the highest 2.5% of children when tested for lead in their blood.”
Tompkins County Department of Health Director Frank Kruppa said the county still uses the 10 µg/dL “level of concern” threshold, but requires doctors to begin discussions with a child’s parents about how to prevent lead exposure at 8 µg/dL.
A single drink of water with 15 ppb of lead isn’t enough to cause any negative effects, but prolonged usage at that level may lead to elevated blood lead levels. More on that below. Also note that lead in the water is only a danger when ingested — showering or bathing in it will not cause any harm.
With that 15 ppb number in mind, let’s look at some of the test results from Enfield and Caroline. After testing in August, three water sources in Enfield and one in Caroline had extremely high levels of lead. January tests also indicated another trouble spot in Caroline:
- Room A-13 in Enfield: 640 ppb in August, 16 ppb in January
- Room B-9 in Enfield: 95 ppb in August, 3.4 ppb in January
- Girl’s lavatory in Enfield: 36 ppb in August, 7.6 ppb in January
- Room 27 in Caroline: 140 ppb in August, 21 ppb in January
- Room 53 fountain in Caroline: not tested in August, 15 ppb in January
Again, the Tompkins Department of Health, in a letter sent to parents in those districts, says that the abnormally high readings in August were due to improper testing and that the January test results were in line with previous tests done in 2006, 2009 and 2012.
A few other things are worth noting here.
First, only five water sources were tested in each school in August. Presumably, this is the case for standard tests which are performed every three years. Ten sources were tested in the January followup. The January test revealed one other water source in Caroline that was at the 15 ppb action threshold.
Second, Kruppa explained that “When the samples are taken, the expectation isn’t that every one of them will be underneath the 15 parts per billion, but that 90 percent of samples taken will be.” In other words, even if one water source in ten in a school is over the 15 ppb threshold the school would still technically pass its inspection.
ICSD has already pledged to replaced the fixtures in room A-13 in Enfield. Additionally, they brought in an outside contractor to test all water sources in Enfield and Caroline. The results of those tests should be available within the next two weeks, according to ICSD Chief Administration Officer David Brown.
Measuring risk and the dark history of lead in the water
It is difficult to measure the precise impact of lead on the human body. What we know for certain is that infants, pregnant women and the elderly are more susceptible to its effects. Beyond that, different people react differently to lead exposure. As noted before, however, the CDC has said that there is no known safe level for lead in the blood stream.
The CDC website says:
Most studies show that exposure to lead-contaminated water alone would not be likely to elevate blood lead levels in most adults, even exposure to water with a lead content close to the EPA action level for lead of 15 parts per billion (ppb). Risk will vary, however, depending on the individual, the circumstances, and the amount of water consumed. For example, infants who drink formula prepared with lead-contaminated water may be at a higher risk because of the large volume of water they consume relative to their body size.
The website later cites a 2004 study based on lead contamination in the water supply in Washington, D.C. That report contains the following conclusion:
Of the 201 residents from 98 homes with water lead levels >300 ppb tested for BLLs [Blood Lead Levels], all had BLLs below CDC’s levels of concern (10 µg/dL for children aged 6 months–15 years and 25 µg/dL for adults) (Table).
This seems reassuring, considering that a consistent ingestion of water with 300 ppb of lead is much scarier. However, that study was later challenged in a paper by Marc Edwards, a professor of Civil and Environmental Engineering at Virginia Tech. Edwards’ paper lead to a congressional review of the 2004 study, which found the study to be “wildly incomplete” and “scientifically indefensible.”
Edwards has continued his work in ensuring water safety around the country, including heading up a task force on the Flint water crisis.
In an email correspondence with Edwards, we asked him to address a few specific concerns expressed by some parents at the Enfield meeting.
One parent was concerned that some unlucky student might return from break, take a drink from a water source that had been idle for a time, and get a “blast” of highly lead-contaminated water.
“Yes, the ‘blast’ issue is a real concern,” Edwards confirmed. “One 250 mL drink of water [approximately 8 oz.] at 600 ppb can increase blood lead from 0 to about 2 µg/dL. Three drinks would be expected to put a child over 5 µg/dL.”
ICSD officials pointed out that the water systems would have been flushed and running by the time that children returned from the break, so this particular risk should not be a concern.
We also asked Edwards if a child drinking regularly from one of the sources at or near 15 ppb since returning to school in September would be at risk, to which he replied simply: “15 ppb over a period of four months is also too much lead.”
A study co-authored by Edwards in 2014 came to the following conclusion:
If the Blood Lead Level (BLL) cutoff was set to the new and more stringent level of 5 μg/dL, then 24 ppb of lead in water is predicted to cause 50 percent of the population to exceed that BLL cutoff, and 7 ppb is predicted to cause 25% of the population to exceed the cutoff.
This data was based on one-to-two year olds, but Edwards said, “Risk would not change much between 1-2 or 5-6 year olds.
More specific numbers for every water source in a school, both in “first draw” and “second draw” scenarios (that is, whether the water has been sitting in the pipes for several hours or has been recently used) would be needed to make a more precise determination of the level of risk.
There was also a Canadian study from 2015 that estimated that an increase of 1 ppb of lead in water “would result in an increase of 35 percent of blood lead (in young children) after 150 days of exposure.”
It further concluded that “water lead concentrations well under the current drinking water guidelines in Canada (10 ppb) and the United States (15 ppb) could have an impact on blood lead levels of young children after long-term exposure.”
Summing up
Unfortunately, there are simply too many variables to weigh to make a judgement as to the danger posed by the lead levels in Enfield and Caroline Schools.
If, as ICSD claims, all water sources were properly flushed before students returned to school and the risk of a “blast” of leaden water was eliminated, then that would be a major concern addressed.
It will also depend on the results of ICSD’s more comprehensive study of all water sources in the buildings. If the “action level” water sources are limited to one or two in each school, then it could be argued that any given child would not drink often enough from those specific sources to cause substantial harm.
It is, of course, up to each parent whether or not they want to get their child tested for lead. The aim of this article was not to raise alarm, but to provide information and perspective for any families who are concerned about this issue.
[do_widget id= text-61 ]