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#712 - Children In Harm's Way, 22-Nov-2000

by Rachel Massey*

A new report by a group of physicians says that millions of
children in the U.S. exhibit learning disabilities, reduced IQ
and destructive, aggressive behavior because of exposures to
toxic chemicals.[1] "Neurodevelopmental disabilities are
widespread, and chemical exposures are important and preventable
contributors to these conditions," the report says (pg. 117).

Titled IN HARM'S WAY, the report was written by physicians Ted
Schettler and Jill Stein and two of their colleagues and was
published by Greater Boston Physicians for Social Responsibility
in partnership with the Clean Water Fund. IN HARM'S WAY links
toxic exposures during early childhood, or even before birth, to
lifelong disabilities including attention disorders, reduced IQ
and poorly-controlled aggression.

IN HARM'S WAY reviews scientific and medical information on a
range of toxins to which most or all American children are
exposed, and draws links to the rising number of children
diagnosed each year with abnormal brain development or function.
The report is a call to action for everyone interested in
children's welfare and the future of our society. To avert brain
damage in growing numbers of children, we have to reclaim our
government from corporate special interests, the report
concludes.

Developmental disabilities such as autism, attention deficit
hyperactivity disorder (ADHD), dyslexia and uncontrollable
aggression currently affect an estimated 12 million children
under age 18 in the U.S. -- almost one child in five.
Furthermore, the incidence of some of these disabilities appears
to have increased dramatically in recent decades. For example,
nationwide, the number of children classified with learning
disabilities and placed in special education programs increased
191% between 1977 and 1994. The number of children taking the
drug Ritalin to combat attention deficit hyperactivity disorder
(ADHD) has approximately doubled every 4 to 7 years since 1971.
Experts estimate that autism rates have risen from around 4 per
10,000 in the early 1980s to between 12 and 20 per 10,000 in the
1990s. According to a recent article in US NEWS AND WORLD REPORT,
the number of children in New York classified with learning
disabilities rose 55 percent between 1983 and 1996. [2]

Some argue that reported disabilities are increasing because of
improved diagnosis and rising expectations as children are
required to learn more complicated skills at younger ages. But
many parents, teachers, and physicians who work with children
think these explanations are only partially correct because "they
can not imagine that such disabilities escaped notice in the
past," the report says. (pg. 11)

Experts may argue about the exact number of children suffering
from individual disorders, but the undisputed reality is that
huge numbers of children currently suffer with serious
developmental disabilities and they are exposed to many toxic
chemicals that are known to produce such disabilities. "We
believe we can no longer ignore the mounting evidence that
chemical exposures contribute to the epidemic of developmental
disabilities," the report says. (pg. 9)

IN HARM'S WAY walks us through a sampling of neurotoxic
substances to which many or all American children are exposed --metals
(lead, mercury, manganese); nicotine; pesticides;
persistent organochlorine compounds (e.g., dioxin and PCBs);
solvents, including alcohol; fluoride; and food additives -- and
reviews existing human and animal data on developmental effects
of these chemicals. These effects can vary dramatically depending
on the exact timing of exposures. Tiny exposures that would have
no noticeable effect at most stages of development can produce
devastating permanent damage if they occur during a "window of
vulnerability" when certain organs are developing rapidly. (pg.
9)

Here is a sampling of the toxins that can misdirect the
development of a child's brain.

-- Lead exposure in infants and children is associated with
attention deficit, aggression, and reduced IQ. Blood lead levels
below those labeled "safe" by U.S. Environmental Protection
Agency (EPA) are associated with learning problems, and no
threshold has been identified below which adverse effects do not
occur. Young monkeys exposed to lead show symptoms including
heightened distractability and inappropriate responses to
stimuli. One million American children currently live with blood
lead levels above the threshold recognized by EPA as affecting
behavior and cognition. Millions more would be added to this list
if EPA's threshold were updated to take account of the most
current science on the effects of lead in children.

-- At low doses, mercury exposure can produce impairments in
language ability, attention, and memory; at high doses it can
cause mental retardation, vision problems, and problems walking.
Mercury enters the environment through waste incinerators and
coal-burning power plants. It bioaccumulates in fish in its most
toxic form, methylmercury (see REHW #597). The EPA estimates that
1.16 million women of childbearing age "eat sufficient amounts of
mercury-contaminated fish to pose a risk of harm to their future
children." (pg. 64)

-- Many pesticides kill insects by exerting a toxic effect on
cells in the nervous system. Not surprisingly, such pesticides
can disrupt the development and functioning of the human nervous
system by the same mechanisms. Animal studies show that
neurotoxic pesticides can produce permanent changes in brain
structure and functioning when exposures occur on a single
critical day of development. For example, some effects occurred
in newborn mice if exposures occurred on day 10 of development,
but not if exposures occurred on day 3 or 19. (pg. 82)
Short-lived "pulse" exposures may have devastating developmental
effects and yet can be difficult or impossible to identify after
the fact (see REHW # 648).

-- One pesticide exposure study examined children in two Mexican
communities. The two communities were very similar in ethnic
composition and culture, but one community practiced
chemical-intensive agriculture while the other used few farm
chemicals. Children in the community with chemical-intensive
agriculture scored substantially lower on measures of memory,
physical stamina and coordination, and had trouble with ordinary
children's activities such as drawing a simple picture of a
person. (pgs. 82-83) Children in the pesticide-exposed group also
displayed more aggressive behavior than their unexposed
counterparts (see REHW #648).

-- Dioxins and polychlorinated biphenyls (PCBs) are
organochlorine compounds that bioaccumulate in fatty tissue and
are found at significant levels in human breast milk. Both animal
and human studies show strong links between these pollutants and
developmental disorders. Monkeys exposed before birth to dioxin
in the range of human breast milk contamination levels were
impaired in their ability to reverse a learned behavior in
response to new stimuli. Young monkeys exposed to PCBs at levels
typically found in human breast milk showed retarded learning as
well as abnormally repetitive behavior. Studies of human children
have found lowered IQs associated with PCB exposure in the womb,
and a study of babies whose mothers ate PCB-contaminated fish
from Lake Ontario found impaired development including abnormal
reflexes and startle responses. (pgs. 76-79) These are just a few
of the studies covered in IN HARM'S WAY.

Government officials set "safe" exposure levels based on
individual chemicals. But in the real world children are exposed
to many chemicals simultaneously. Such multiple exposures can be
far more damaging than exposure to single chemicals. For example,
one study found that certain combinations of pesticides produce
changes in thyroid levels that are not observed when the
chemicals are tested individually, and thus the combination may
produce unexpected developmental effects (see REHW #648). Proper
thyroid levels are essential for brain development. Other studies
reveal that exposure to a combination of mercury and PCBs, two
pollutants that accumulate in fish, can produce even greater
effects on neurological development than either pollutant alone.
(pg. 67)

Under our current regulatory system, industrial chemicals need
not be tested for toxicity before they are marketed. (pg. 108)
EPA estimates that somewhere between 2400 and 4000 industrial
chemicals now on the market are neurotoxic. (pg. 107) However,
this number is "highly speculative" (pg. 107) because most
chemicals in commercial use have not been tested for
neurotoxicity. EPA's Toxics Release Inventory (TRI) -- which
covers just 625 out of 80,000 industrial chemicals -- reported
that nearly a billion pounds of known neurotoxins were released
directly into air and water in 1997. (pg. 103) Pesticides must be
tested before marketing, but not for toxicity to the nervous
system. Of 890 pesticide "active ingredients" EPA believes 140
are neurotoxins. Some 20 million U.S. children under age 5 eat an
average of 8 different pesticides on their food each day. (pg.
106)

The authors of IN HARM'S WAY point out that there is no reason to
delay protecting our children; we don't need more scientific
information before taking precautionary action. "We should not
need to identify with certainty exactly how much and through what
mechanism a neurotoxic pesticide impairs brain development before
coming to the conclusion that public health is not protected when
the urine of virtually every child in this country contains
residues of these chemicals. ... We do not need to exhaustively
understand the mechanism by which methylmercury interferes with
normal fetal brain development before concluding that it is not
acceptable for freshwater and many ocean fish to be sufficiently
contaminated with mercury to threaten developing brains. We know
how to reduce the environmental releases of mercury so that fish
are once again safe to eat regularly. We can modify manufacturing
practices so that lead use in products goes steadily down instead
of up. We can eliminate or modify outmoded technologies that
produce the dioxin that contaminates fetuses and breast milk. We
know how to do these things." (pgs. 121-122)

In order to do these things, we have to take back control of our
regulatory system. As things stand now, corporations that benefit
financially by exposing children to toxic substances are accepted
-- even by most environmentalists -- as valid "stakeholders" in
the process that determines "safe" levels of exposure. As a
result, we have failed to protect our children from industrial
poisons. As the authors of IN HARM'S WAY put it, "The role of
special interests in the regulation of environmental chemicals is
an important matter for public debate, as it has direct relevance
to the neurological development of children now and in the
future." (pg. 121) In sum, our current regulatory system is like
a trial in which the criminal defendant gets to serve on the
jury. If we want to have children who can play, think and learn
normally, we will have to change corporations and our government
so that protecting brain development comes ahead of protecting
profits.

=====

* Rachel Massey is a consultant to Environmental Research
Foundation.

[1] Ted Schettler, Jill Stein, Fay Reich, Maria Valenti, and
David Wallinga, IN HARM'S WAY: TOXIC THREATS TO CHILD DEVELOPMENT
(Cambridge, Mass.: Greater Boston Physicians for Social
Responsibility [GBPSR], May 2000). Available on the web at
http://www.igc.org/psr/ or as a paper copy from GBPSR in
Cambridge, Mass.; telephone 617-497-7440.

[2] Sheila Kaplan and Jim Morris, "Kids At Risk," US NEWS AND
WORLD REPORT Vol. 128, No. 4 (June 19, 2000), pgs. 47-53.