Family Forum / Pregnancy / Breastfeeding / February 2005

I posted about it the other day
(http://groups-beta.google.com/group/misc.kids.breastfeeding/msg/953a028a11c6ab50
?dmode=source)
but no one replied.  I guess you and I are the only ones interested...

I think that's wise.

I wish the article had mentioned which areas were affected.  I know
that one of the ones I read mentioned New Jersey, and another said that
it was a problem in areas that get their water from the Colorado river,
but I'm wondering if I need to be concerned in my area.  I'm not even
sure who I would contact to find out!

But it's not in everyone's breastmilk, so don't freak out.  I think
most people eat enough iodized salt that they're getting more than
enough iodine on a daily basis, don't you?  Salt's one of those things
they tell you not to limit during pregnancy.  Maybe this is part of the
reason why?

Anyway, there's no reason to upset yourself over one study.  I don't
even think that it has been peer reviewed.  They could look into it
further and figure out that the whole thing was flawed (of course,
we'll never hear about that).

Amy (spent all day yesterday at a rocket lab, did not drink the water

Response from Jane Heinig and Paula Benedict:
Dear Friends,

Recent news accounts indicate that perchlorate contamination in breast
milk of California mothers has reached the point where infant exposures
exceed safe levels.  The study cited to support this view was published
on the web on Feb. 23, 2005. (1)  It is important that professionals
understand that the study cited includes milk samples from only 5 women
in California and no direct measurements were made of infant exposure.

While we are all concerned about the presence of perchlorate
contamination in the environment, women wh o breastfeed their infants
should not stop breastfeeding based on this report.  This study does not
provide sufficient information about the average perchlorate content in
California mothers' breast milk, how much is transferred to the infant,
and what, if any, are the adverse effects of such exposure.

Perchlorate is both a naturally-occurring and manmade chemical found in
the environment. The chemical is used in a variety of manufacturing
processes including the manufacture of rubber, paint and enamel
products, fireworks, highway flares, and rocket fuel.  Human
contamination comes from water and food exposures (including drinking
water, cow's milk and vegetables). Perchlorate competitively inhibits
iodine uptake in the thyroid gland, potentially reducing thyroid
function. (2) Impairment of thyroid function in expectant mothers may
affect the fetus and newborn, including delayed development and
decreased learning capacity. (3) However, published studies examining
the adverse effects of prenatal exposure to perchlorate in human
populations have produced mixed results. (4-7) No studies have been
published describing measured infant intakes of perchlorate (through
breast milk) or prevalence of adverse effects of exposure among
breastfed infants.

The study cited by the press has several important limitations:

.        While the researchers state that the participating mothers were
randomly selected, no description of their population sampling method is
provided.
.        A total of 36 mothers from 18 states participated in the study
and 5 were from California.  Such a small sample size, however it was
obtained, is not sufficient to be representative of the general
population.
.        There is no description of the methods used for milk sampling.
Timing since the last feed a nd the completeness of milk expression
strongly influence values in chemical tests of human milk.  Perchlorate
levels are particularly likely to be associated with recent exposure. An
expert panel has provided guidelines for milk sampling for chemical
testing. (8) There is no evidence that these guidelines were followed.
.        The researchers did not directly measure infant perchlorate
exposure.  Hypothetical exposures were estimated from calculations using
assumed milk volume and a transfer rate of the chemical predicted by
experiments in rats.   No information is provided about the age of the
infants in the study or their consumption of other foods and fluids.
Therefore, actual infant exposures are likely to vary widely from the
estimated values.
.        The researchers suggest that iodide levels in the milk samples
were inversely associated with perchlorate concentration (at the highest
levels of contaminat ion) but the sample size was so small that they
were not able to examine this association statistically.

Since the action of perchlorate is to bind iodide, women may wish to
discuss their exposure risk with their physicians and consider
increasing their iodide intake through switching to iodized salt or
consuming a supplement.  This study does not provide any evidence that
California women should not breastfeed their infants.

Jane Heinig, PhD, IBCLC and Paula Benedict, MPH, RD

References
(1) Kirk AB, et al. Perchlorate and iodide in dairy and breast milk.
Environ Sci Tech, pre-publication on web.
(2) Greer MA, Goodman G, Pleus RC, Greer SE. Health effects assessment
for environmental perchlorate contamination: the dose response for
inhibition of thyroidal radioiodine uptake in humans. Environ Health
Perspect. 2002;110:927-37.
(3) Technical Briefs: Perchlorate:  Questions and Answers. J of Envir
Health Nov 2004; 67, 4.
(4) Kelsh MA, et al. Primary congenital hypothyroidism, newborn thyroid
function, and environmental perchlorate exposure among residents of a
Southern California community. J Occup Environ Med. 2003;45:1116-27.
(5) Brechner RJ, et al. Ammonium perchlorate contamination of Colorado
River drinking water is associated with abnormal thyroid function in
newborns in Arizona. J Occup Environ Med. 2000;42:777-82.
(6) Crump C, et al.  Does perchlorate in drinking water affect thyroid
function in newborns or school-age children? J Occup Environ Med.
2000;42:603-12.
(7) Li Z, et al. Neonatal thyroxine level and perchlorate in drinking
water. J Occup Environ Med. 2000;42:200-5.
(8) Berlin CM Jr, et al. Conclusions, research needs, and
recommendations of the expert panel: technical workshop on human milk
surveillance and research for environmental chemicals in the United
States. J Toxicol Environ Health A. 2002 Nov 22;65(22):1929-35.

Response from Tom Hale:

I have reviewed this article on Perchlorate in cow and human milk. While
I have some problems with their methods of collecting milk (both cow and
human), the data is still somewhat preliminary, they simply have too few
samples to really make much of a case. They also tried to make the case
that the higher the perchlorate, the less iodide in milk. While this
seems logical, in two of their human samples (TX76, TX78), the highest
milk iodide levels reported were in mothers at supposedly high
perchlorate levels (11.3 and 12.7 ug/L). Seems kind of odd! In several
other cases(4) the higher the perchlorate level the less the
iodine...but this was only 6 cases out of 36 mothers.

The most important factor for mothers to understand, is that with high
perchlorate levels, the amount of iodine in their milk MAY be lower,
we're not really sure at this point. But has the incidence of hypoth
yroidism in breastfed infant increased lately? Not that I know of. I
just spoke with one of our Pediatric endocrinologists and they are not
seeing any change in the incidence of hypothyroidism as of yet.

These authors also suggest that mothers might want to supplement
themselves with higher iodine levels. Because iodine is actually pumped
into human milk, sometimes at high levels, I worry that the random
supplementation of mothers with iodine may actually overdose some
infants and cause more problems than we had to begin with. This is
because the overdose with iodine is sometimes much worse than the
underdose.

So at this time all mothers should continue to breastfeed and not worry
about the perchlorate issue. Have their pediatricians evaluate their
infants at the routine visits for hypothyroidism (which every
pediatrician does anyway), and not to worry about this contaminate.

In Summary:
1)--Perchlorate inhibits the uptake of iodine by the thyroid gland, and
its secretion into hum an milk.
2)--The only known complication is hypothyroidism, which is easily
treated with supplements of iodine, or in rare cases thyroxine.
3)--Be extremely cautious of supplementing yourself with extra iodine,
you may actually do more harm to your infant by overdosing with iodine,
than by underdosing with "perchlorate".

Lastly, this is the third time in the last several years that
environmental contaminates have been found at low levels in breastmilk.
This and a lot of other data is suggesting that we humans simply must
become more proactive at voting for candidates that support
environmental standards because our whole future depends on it.

Tom Hale Ph.D
Professor of Pediatrics
Texas Tech University School of Medicine

*    Hasn't anyone else read the article about the rocket fuel chemical
*called perchlorate found in breastmilk???  Researchers studied woman
*across the United States and found high levels of this chemical in all
*the women's breastmilk.  Levels of perchlorate were higher in
*breastmilk than water or cow's milk.  The levels of this dangerous
*chemical seem to be concentrated in higher amounts in women's
*breastmilk!  Perchlorate can negatively effect a baby's brain and their
*thyroid.  The article also discussed how baby rats who breastfed and
*were exposed to perchlorate through their mother's milk had changes in
*brain morphology and thyroid function.

But recent and ongoing studies continue to show that breastmilk-fed babies
have lower rates of certain infectious diseases, infections, possibly
neoplasias, and metabolic diseases, as well as having either the same or
slightly higher IQs, than formula fed babies. So, it seems there is
still no reason to stop BFing or to worry that BF is bad for your baby. It
does suck that there are so many environmental contaminants in breastmilk
(and cows' milk and water and food and well, everything) but breastmilk
still looks like the best of the available options.

Hi everyone,

As part of my thesis research, I studied persistant pollutants
(pesticides, flame retardants, etc) in dolphins.  One of the aspects we
focused on was the transfer of contaminants from mother to offspring
via lactation.  A lot of my background research included studies on
contaminants in human breast milk (PBDEs, common flame retardants,
which are banned in parts of Europe and California now, were the hot
topic during my research).

Yes, if you are exposed to contaminants they will be readily
transferred to your child via breastmilk. As mentioned in some of these
posts, the sample size in the study (which I've only browsed) was very
small.  Research done on lab rats typical uses concentrations that you
would not find in the normal population.  It is common to expose
animals to extremely high concentrations to see what negative response
will be elicited. Your average mother is not exposed to high enough
concentrations of chemicals to pose a serious threat.  There has not
been enough research done.

This article is what I call 'sexy science.'  It gets people interested,
it gets people talking.  It gets mother's worrying.  Any research
involving breastmilk is going to get a lot of press.  That's pretty
much how PBDEs got banned.

Maybe this will make us worry more...but over the course of my research
I found extremely high concentrations of pesticides in dolphins....an
open ocean species.  These are pesticides that are applied on land and
make their way to the ocean through run-off and atmospheric transport.
We are surrounded by a lot of nasty chemicals.

I've been directly working with these nasty chemicals for almost five
years up until the birth of my daughter 7 months ago.  She nurses like
a crazy woman.  I have no doubt that there are trace levels of these
contaminants in my breast milk....but there are going to be trace
levels in our water supply, in cow's milk, goat's milk, soy milk,
produce, etc. etc. etc.

Yes, stay educated.  Yes, talk to your pediatricians if you are
worried...but please don't worry too much and please don't stop
breastfeeding.  If you are worried about exposure just get a brita
water filter and try to buy organic produce & meats.  I'd be a lot more
worried about the hormones added to meat products than by rocket fuel.

Also, I whole-heartedly agree with Dr. Hale about getting
environmentally-conscience politicians in office.  We are going down a
very scary road here in the US.

The problem I have with this study is that they did the water OR cow's milk
vs. breastmilk level comparison. Don't moms mix formula (cow's milk) WITH
water? When combined in this fashion, what is the true level comparison?

Marie
DD-1yo

It was put out by the dairy loby.

This is very very old news.

this has been researched intensively, and no adverse effects ahs been
found.

See: www.borstvoeding.com/abon/bf_toxins.html