The EPA—again—fails to protect child health
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| Perchlorate is a key ingredient in fireworks and explosives |
While an official decision hasn't
been published yet, this week it was reported that Andrew Wheeler, the
administrator of the EPA, decided the agency will not impose limits on
perchlorate to protect human health. The agency was required to establish drinking
water standards for the chemical by next month.
To be clear, everyone reading this
article almost certainly has perchlorate in their bloodstream. Perhaps more
importantly, perchlorate is even found in amniotic fluid and umbilical cord blood, so
fetuses are being exposed.
If we are all exposed, then why
would the EPA choose not to regulate it unless it is safe?
Is perchlorate hazardous?
The answer is "Yes."
Perchlorate can interfere with normal brain development in our children.
Perchlorate is a molecule that looks like iodine to
our bodies. Iodine is important because our thyroid glands need it to make
thyroid hormone.
The right amount of thyroid hormone
is essential for the human brain to develop properly. This is true from early
on in the first trimester of pregnancy well into the second year of childhood.
Perchlorate can block the ability of
our thyroid glands to get enough iodine to make the proper amount of thyroid
hormone.
So, perchlorate is most certainly
hazardous. If we are all exposed—even pregnant women and their fetuses—then
perchlorate has the potential to damage the developing brain.
Of course, perchlorate is not the only chemical the fetus and
infants are exposed to that can harm brain development, and they very likely
produce an additive effect.
There are many scientific studies in
humans to try and determine how much perchlorate it takes to harm our children.
Recognize that if we are already exposed to that amount of
perchlorate, it is already harming our children and they will never recover
from its effects.
But it is complicated.
Some studies have shown that
measures of perchlorate exposure are associated with lower levels of thyroid
hormone, while other studies have not found this. One study showed that perchlorate was
associated with lower thyroid hormone in adolescent girls and boys.
We know that perchlorate and
iodine compete to be taken up by the thyroid gland. Thus, if
there is more perchlorate than iodine, perchlorate wins. If the opposite is
true, perchlorate loses.
So, for any exposure level of
perchlorate, its ability to block iodine is dependent upon the iodine level.
This is very likely part of the explanation for why only some studies show an
association between higher perchlorate and lower thyroid hormone.
But one study—the only one of its kind—showed
that pregnant women with higher levels of perchlorate exposure had children
with lower IQ levels.
The conclusion from the scientific
evidence appears to be that some people are being damaged by perchlorate today.
That seems like a weak
statement—unless your child is one of them.
Where does perchlorate come from?
Most of the environmental
perchlorate we are exposed to is man-made. It is
both easy and cheap to make and it is used primarily as an ingredient in
explosives. Fireworks, air-bags, rocket fuel, ammunition are all important
sources of perchlorate.
Over many decades of careless
disposal, many parts of the country have become heavily contaminated—to the
extent that major river systems have
measurable levels of perchlorate.
Much of this contamination has come
from military installations—the Department of Defense. And, using your tax
dollars, they have fought hard to avoid having to clean
it up (again with your tax dollars).
The Food Safety Division of the Food
and Drug Administration has even approved the use of
perchlorate in food packaging!
So, perchlorate comes from the food
you eat, from various beverages, and from the water you drink. The EPA can only
regulate what is in your drinking water. But, they are supposed to consider the
other sources of perchlorate, so that what you would get in drinking water
would not add up to "too much."
The pattern is unnerving
When the EPA first performed a risk
assessment on perchlorate in the 1990s, they initially proposed a safe level in
drinking water to be one microgram per liter of water. This is about a drop of
water in an Olympic size pool. Massachusetts, for
example, currently has a drinking water standard of two micrograms per liter.
So, the most important federal
agency charged with protecting human health and the environment has
"evolved" from a health protective proposal to no regulation at all.
You are simply on your own, without
knowing where perchlorate is coming from in your environment.
A final thought
I grew up in southern Indiana on the
banks of the Ohio River directly opposite Louisville, Kentucky.
In those days, cities along the
river sent raw sewage directly into the river. The air on hot summer days was
particularly pungent with the results. It is precisely because of environmental
regulations that this is not the case today.
But the river today is polluted with
many different kinds of contaminants that go unregulated and are just as harmful,
if not moreso. So, we seem to be sensitive to pollution that is obvious—like
the smell of raw sewage.
But we are less sensitive to
pollution that is not obvious—like perchlorate and other chemicals that rob our
children of their intellectual potential.
There is shame in realizing that our
society does not prioritize health outcomes in our children that are not
immediately obvious.
R. Thomas Zoeller is Professor
Emeritus of Biology at the University of Massachusetts Amherst and Visiting
Professor at Örebro University, Örebro, Sweden.
His views do not necessarily
represent those of Environmental Health News, The Daily Climate or publisher,
Environmental Health Sciences.