July 18, 2003
Chemical Pollution Series (Part 1) - Toxic chemicals can cause learning disabilities
In 2002, a series of seven, one-page articles appeared in the New York Times.
The primary goal behind them was to alert people to the types of threats we all face
from environmental pollution - specifically from a group of compounds called Persistent Organic Pollutants or POP's.
Since the collection of data on the distribution and concentrations of POP's (also known as EDC's, BPT's and organohalogens)
in the world's oceans is a focus of our work - it seems fitting to present another take on this issue.
We are grateful to the authors and sponsors of these articles for permission to include them here.
For more information and to view all of the articles go to www.childenvironment.org.
Toxic chemicals can cause
We are physicians and scientists. We
are deeply troubled that an estimated
twelve million American kids suffer
from developmental, learning, or
behavioral disabilities. Attention deficit
disorder affects three to six percent
of our schoolchildren.
These disabilities are caused by a
complex interplay of genetic,
environmental, and social factors.
Evidence reviewed by the National
Academy of Sciences indicates that
toxic chemicals contribute to these
problems. Environmental factors take
on great importance because they
can be prevented.
What We Know
Studies show that lead, mercury,
industrial chemicals, and certain
pesticides cross the placenta and enter
the brain of the developing fetus
where they can cause learning and
behavioral disabilities. This is true in
young animals - and in young children.
Exposures to organophosphate
pesticides during pregnancy can
result in abnormally low brain weight
and developmental impairment in
offspring. A Duke University study
conducted on rodents found that
hyper-activity and brain cell death can
be caused by small exposures to the
widely used organophosphate pesticide
Dursban.That study led to the ban on
the production and sale of Dursban.
But similar-acting pesticides are still
on the market.
A University of Arizona study found
that children exposed to a combination
of pesticides before birth and through
breast milk exhibited less stamina, and
poorer memory and coordination, than
Mercury released by coal-fired power
plants contaminates waterways and
accumulates in fish. Many thousands
of the pregnant women in America
who eat fish consume enough mercury
to potentially harm their children's
neurological development. Some states
warn that children should not eat more
than a can of tuna per week; based on
EPA guidelines, a twenty-pound child
may exceed a level considered safe for
the most sensitive populations with
just 1.3 ounces.
Though PCBs have been banned,
residual PCBs still do much damage.
Children whose mothers ate Great
Lakes fish contaminated with PCBs
showed lowered IQs and shortened
attention spans. And these effects on
intelligence and behavior have been
shown to persist throughout childhood.
A Dutch study confirmed that increased
maternal levels of PCBs can impair
cognition in infants.Young monkeys
exposed to PCBs at low levels show
learning disabilities and hyperactivity.
What We Can Do
There is much that parents can do to
protect their children, beginning with
the elimination of many pesticides
both outside and in the home. And
the choice of a wise diet. There are
more suggestions on our website,
But we must do more.We have
enough scientific evidence to phase
out those chemicals known to harm
children's behavior and development.
If a medicine caused these problems
in kids, we'd ban it.
We don't allow food or drugs to be
sold before being shown to be safe.
Yet there are thousands of chemicals
on the market that affect human
biology and have never been tested.
Most importantly, we must demand
that new chemicals be tested for safety
before being allowed on the market.
We do not have a system that does
A summary of the supporting
scientific evidence, and a list of
scientific endorsers, can be found
- To download a PDF version of this article - click here