Health Officials Defuse Lead Concern, Promote Awareness

At an emergency City Council meeting, officials from the Los Angeles County Department of Public Health soothed the ruffled feathers of city officials and residents in regard to concerns about lead exposure. At the same time, those officials urged parents to be vigilant for the toxic heavy metal.
The meeting was the result of a Reuters story published in April that used blood screens in children for lead elevations to highlight San Marino as an apparent hot spot for exposure. However, department officials warned that the use and interpretation of that data, which was acquired through a public records request, was lacking context.
“I don’t want the data to lead them to believe there is a lead epidemic in San Marino,” said Dr. Cyrus Rangan, director of the Department of Public Health’s Toxics Epidemiology Program, in a follow-up interview.
Rangan and his colleague, Department of Public Health Environmental Health Services Manager Maurice Pantoja, spoke extensively before the City Council at the Wednesday, April 26, meeting to address concerns raised in the Reuters report.
That report, using 163 blood-lead screenings from one census tract (which covers the city west of San Marino Avenue) and 170 screens from a second tract (which covers the other half of the city), determined that 17.18% and 11.18% of those screens, respectively, indicated elevated levels of lead exposure in the tested children.
“These numbers are just too small to make these percentages meaningful,” Rangan explained at the meeting. “If we were talking about tens of thousands of people in the community, then we’re talking about something meaningful.”
Of the western tract’s 163 tests, 28 of the children were recorded as having an elevated lead level, which means their body contains 5 or more micrograms of lead per deciliter of blood. However, the county and state record the presence of lead in amounts smaller than 5 micrograms as actually being 5.
They do that for a number of reasons, Rangan said. One is simply because conventional laboratory equipment cannot precisely identify the amount if it’s below 5 micrograms but still higher than zero. (Or, simply stated, any amount that is smaller than 5 is recorded as “less than 5 micrograms.”)
Even though the amount is below what is considered “elevated,” that data is still recorded as being at least 5 micrograms out of an abundance of caution, Rangan said.
In a situation in which a pool of data would collectively indicate an elevated amount, but is not high enough to trigger public intervention, the added data could be enough to push the bottom line past that threshold for intervention.
In actuality, only two of the tested children in the western tract had truly elevated levels — one with 6.8 micrograms per deciliter and the other with 6. In the eastern tract, 19 tested children were recorded with elevated levels, but just one was truly elevated, at 6 micrograms per deciliter.
The screens were taken by pediatricians from 2011 to 2015 and the data reflects unique patients. Rangan, himself a pediatrician, said the American Academy of Pediatrics recommends that all children ages 1 and 2 be screened for lead, regardless of whether there are risk factors.
However, the low testing numbers for San Marino indicate that isn’t always happening.
“The reason for that is that pediatricians, by and large, don’t always follow through with that recommendation,” Rangan said.
In a follow-up interview, Rangan said that some pediatricians, in his experience, will hesitate to push an inconvenience upon families if they have no reason to believe there is lead exposure.
However, Rangan said, despite having an image as a modern metropolis compared with older cities on the East Coast, Los Angeles ranks in the top 10 nationally for old housing stock. Because lead-based paint — universally considered to be the dominant source of lead exposure — was only banned in 1978, health officials assume virtually all homes in L.A. County contain some lead-based paint.
“When you come down to it, every kid has a risk factor of some kind,” Rangan said. “One of the reasons we like age 1 is because we like to take a look at a lot of things like hemoglobin levels already.”
That age is a “perfect storm” of lead risk, Rangan said, because children in that age range tend to crawl all around the house and do not hesitate to put things into their mouths. Making matters worse, paint tends to start peeling and chipping where walls meet the floor and any paint dust created from opening and shutting windows settles into the carpet.
The brain also is developing significantly at that time, with main synapse wiring usually finishing before age 1.
“After that, your brain is doing all sorts of rewiring,” Rangan added. “The formation of what we call the ‘architecture’ is generally between age 1 and 2 and this is a critical time for brain development.”
Among the long-term consequences of prolonged lead exposure at an early age is inhibited brain development, which can result in some developmental and learning disabilities. Intelligence quotient, or IQ, test results have been shown to be lower in kids who had prolonged and large lead exposure as infants.
On top of the relatively low number of tests collected from San Marino children, Rangan pointed out around half were ages 4 and 5, which is outside of the typical screening age. That could possibly suggest that parents or doctors were aware of a recent remodeling or renovation that results in exposure risk.
“In general, when older kids get tested, it’s because the pediatrician and family have determined there is a risk factor,” he said.
The state requires children who are beneficiaries of certain public health care programs to be regularly screened for lead exposure, which may be why there are several areas throughout L.A. County and the surrounding counties that have hundreds or even thousands more children screened than San Marino does. Census tracts tend to have between 4,000 and 7,000 residents each.
According to the data presented in an interactive map on Reuters’ story, with some exceptions, the tracts with the highest percentages of tests recorded as having elevated lead levels tend to have lower numbers of tests.
Tests that show fewer than 5 micrograms of lead per deciliter of blood are not considered a problem by doctors, as lead is a naturally occurring metal and people can often have acute exposures or ingestions of lead. A result between 5 and 10 micrograms is supposed to trigger a follow-up test in a few months to determine how the elevation changes. Any test above 10 micrograms triggers a response from the Department of Public Health to determine the source of the exposure.
Because the worst test in San Marino registered at 6.8 micrograms, the county had no reason to intervene, so city officials were not directly informed of the lead screening results.
“Because they’re less than 10 [micrograms of lead], we don’t know the causes of the lead exposure,” Pantoja said. “There are a lot of things that aren’t necessarily in the house.”
The best way for the Department of Public Health to evaluate lead exposure, Rangan and Pantoja said, is to have more screenings for the best data pool.
“We’re looking at a very, very tiny number,” Rangan emphasized.

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