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 Elevated levels of lead and arsenic have long been documented in the
air and soil surrounding facilities that recycle batteries. The
Exide plant, located just southeast of downtown Los Angeles,
recycled 11 million car batteries a year and released 3,500 tons of
lead over 30 years. It closed in March 2015 as part of a legal
settlement for hazardous waste violations, researchers note in
Environmental Science and Technology.
Blood tests have previously documented the presence of lead and
arsenic in people living near battery recycling facilities, but lead
only lingers in the bloodstream roughly four weeks after exposure.
To examine prenatal and early childhood exposure to lead and
arsenic, researchers tested 50 baby teeth from 43 children whose
parents had signed on to the "Truth Fairy" project and donated one
or two teeth their kids had shed. The families all lived within two
miles of the Exide plant.
"All the children we measured were exposed to lead before they were
born," said lead study author Jill Johnston of the Keck School of
Medicine at the University of Southern California in Los Angeles.
"Lead is a well-known toxicant that harms brain development, even at
very low levels," Johnston said by email. "It is linked with
aggressive behavior, ADHD, and delayed learning, and . . . lower
birthweight."
There is no safe level of lead exposure for kids.
Lead paint remains the most common source of lead exposure for U.S.
children, Johnston said. But the tonnage of lead-acid batteries
recycled in U.S. smelter facilities has more than doubled over the
last 40 years and the U.S. is the second largest producer of
recycled lead in the world.
Batteries crushed and melted in smelters can release dust that
escapes into the air through factory smoke stacks and then settles
in soil and on surrounding roofs and yards. People can then be
exposed to lead by breathing contaminated air, playing or working in
the yard, or by contaminated soil brought into the homes by wind,
pets or shoes.
Baby teeth grow in layers starting in the middle of pregnancy and
continuing into the first year of life. The layers of enamel on the
exterior of the tooth look a lot like tree rings, allowing
researchers to see if and when children might have been exposed to
pollutants like lead, including after birth, when infants have a
high risk of exposure from crawling and putting their hands in their
mouths.
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In addition, researchers examined state records on soil
contamination in the neighborhoods where the study participants
lived. They found half of the soil samples tested had lead
concentrations of at least 190 parts per million (ppm), more than
double the state cap of 80 ppm. Fourteen percent of the soil samples
exceeded 400 ppm.
Baby teeth had the highest concentrations of lead when kids lived
where the soil also had the highest concentration of lead, the study
found.
Of the 43 children, 20 also had detectable levels of arsenic from
prenatal exposure and 17 kids had evidence of post-natal arsenic
exposure.
The study focused on whether environmental lead levels correlated
with the evidence of exposure in the teeth, and didn't compare the
kids' lead exposure to that of other children in neighborhoods
without a nearby battery plant.
It also wasn't a controlled experiment designed to prove whether or
how the Exide battery plant contributed to lead or arsenic exposure
in nearby families, nor did it assess specific negative health
outcomes from lead exposure.
Still, the connection between lead in baby teeth and industrial
pollution is plausible, and has been documented in many other
studies, said Aaron Reuben, an environmental health researcher at
Duke University in Durham, North Carolina, who wasn't involved in
the study.
"Lead deposited in soil near homes will find its way into the bodies
of children, whether through inhalation of dust or ingestion of
soil," Reuben said by email. "I am left with little doubt that
children in this community are being exposed to higher levels of
lead than their neighbors whose soil was not contaminated in the
past."
SOURCE: https://bit.ly/2Q4p0WF Environmental Science and Technology,
online May 6, 2019.
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