 Contrary
to touted calcium benefits, drinking milk has been found to hold an
adverse health affect. According to a study, a chemical associated
with rocket fuel--perchlorate--has appeared in most samples of mother's
breast milk and store-bought cow's milk from 23 states. Results indicated:
Though exactly where the perchlorate is coming from remains a mystery,
the National Academy of Sciences (NAS) has claimed most of the perchlorate
contamination is derived from the use of rocket fuels, fireworks
and explosives. However, this chemical also occurs naturally in
the atmosphere and is stored in the soil, being found widely in
the U.S. water supply (35 states) and in vegetables such as lettuce.
(Contamination is particularly widespread in California due to the
many current and former defense and space program sites located
there.)
While it's too early to determine whether the perchlorate levels
in the breast and cow's milk samples are dangerous, the chemical
has been associated with thyroid ailments and is particularly dangerous
to children. This is because perchlorate knocks an iodine ion off
of a protein that transports the ion to the thyroid. This can lead
to iodine deficiency, which impairs thyroid development and is believed
to be the main cause of mental retardation in children. And with
the potential problem many Americans have with iodine nutrition,
perchlorate only makes matters worse.
New Safety Limit for Perchlorate
In light of this contamination concern, the Environmental Protection
Agency (EPA) has taken a step toward resolving the problem by setting
a new safety limit for perchlorate exposure level: 24.5 parts per
billion (ppb), in drinking water. (The average level of perchlorate
founding in breast milk is close to half of that, though an NAS
study showed a "safe" intake of perchlorate for a baby
should be set at about 4 ppb.
The new limit is what the NAS recommended in January 2005; the
EPA's preliminary ruling two years ago on perchlorate was 1 ppb,
a number considered too stringent by the Pentagon.
USA Today February 25, 2005.
New Scientist February 24, 2005.
Medical
News Today February 23, 2005
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