Body Burden — The Pollution in Newborns
A benchmark investigation of industrial
chemicals, pollutants and pesticides in umbilical cord blood, July 14,
Not long ago scientists
thought that the placenta shielded cord blood — and the developing baby —
from most chemicals and pollutants in the environment. But now we know that
at this critical time when organs, vessels, membranes and systems are knit
together from single cells to finished form in a span of weeks, the
umbilical cord carries not only the building blocks of life, but also a
steady stream of industrial chemicals, pollutants and pesticides that cross
the placenta as readily as residues from cigarettes and alcohol.
Chemical exposures in the womb or during
infancy can be dramatically more harmful than exposures later in life.
Substantial scientific evidence demonstrates that children face amplified
risks from their body burden of pollution; the findings are particularly
strong for many of the chemicals found in this study, including mercury,
PCBs and dioxins. Children's vulnerability derives from both rapid
development and incomplete defense systems:
A developing child's chemical exposures are
greater pound-for-pound than those of adults. An immature, porous
blood-brain barrier allows greater chemical exposures to the developing
brain. Children have lower levels of some chemical-binding proteins,
allowing more of a chemical to reach "target organs." A baby's organs and
systems are rapidly developing, and thus are often more vulnerable to damage
from chemical exposure. Systems that detoxify and excrete industrial
chemicals are not fully developed. The longer future life span of a child
compared to an adult allows more time for adverse effects to arise.
Ottawa plans to snuff
out flame retardants
This new research has
found that flame retardants have an ability to mimic thyroid hormones; it is
thought that by following that hormonal route, the chemical plays havoc in
laboratory animals, where exposures have been linked to hyperactivity,
impaired learning and decreased sperm counts.
Researchers are finding that flame
retardants don't obey traditional rules of toxicology, shedding light on the
novel ways that some chemicals may still hold dangers, even though they
aren't outright poisonous or don't trigger cancer.
The traditional mantra of toxicologists has
been that the dose makes the poison, or that exposures have to be large to
have an effect, with larger exposures packing more punch than smaller ones.
In experiments with rodents, effects have
been noted on the offspring of rats given only one exposure of 60 parts per
billion, an amount that a few decades ago scientists would have dismissed as
too low to have an impact. To get an idea of the amount involved, a part per
billion equals a single drop of water in a gasoline tanker truck.
The study of 130 mothers
and their children in California's Central Valley revealed that a natural
enzyme in the human body that breaks down toxicants, including commonly used
pesticides, varies to such a degree that some of the population's youngest
members may be virtually defenseless against some chemicals.
From: Public Library of
Science, a peer reviewed Medical Journal
Excerpts of article:
The developing fetus and
young child is particularly vulnerable to certain environmental toxins [46,47,48,49,50].
Over the past three
decades, researchers have found that remarkably low-level exposures to these
toxins are linked with less overt symptoms of toxicity—intellectual
impairments, behavioral problems, spontaneous abortions, or preterm births
The developing fetus and young child is
particularly vulnerable to certain environmental toxins [46,47,48,49,50].
Critical neurodevelopmental processes occur in the human central nervous
system during fetal development and in the first three years of life. These
processes include cortical functional differentiation, synaptogenesis,
myelination, and programmed apoptosis .
Children's exposure to environmental toxins
is insidious. Environmental toxins covertly enter a child's body
transplacentally during fetal development or by direct ingestion of house
dust, soil, and breastmilk and other dietary sources during early childhood
environmental toxins have been linked with higher rates of mental
retardation, intellectual impairment, and behavioral problems, such as
conduct disorder and attention deficit hyperactivity disorder
From a scientific
standpoint, data from epidemiologic studies represent the “gold standard”
for detecting subtle effects of environmental toxins on humans. But
epidemiological studies are expensive to mount, difficult to execute, and
take years to complete. …
More importantly, if
society continues to rely on epidemiologic studies to evaluate the toxicity
of chemicals only after they are marketed, many children will first be
Children must be better
protected from both new and existing chemicals that are known or possible
If there is any lesson
from our experience with environmental toxins, it is that we need to
identify environmental chemicals that are toxic before they are marketed or
widely disseminated. [We already know the chemicals to flameproof beds are
It is time to acknowledge
that the existing requirements for toxicity testing and regulations are
inadequate to safeguard pregnant women and children. Until a formal
regulatory system is developed to effectively screen and identify new and
existing chemicals that are toxic to pregnant women and children, we are
left to await the next epidemic to warn us about an environmental disaster.
Unfortunately, by then we will have once again fouled our nest .