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44 Million Women at Risk of Thyroid Deficiency From Rocket Fuel Chemical
Federal Study Confirms Perchlorate as Widespread Public Health Threat
 http://www.commondreams.org/news2006/1005-02.htm

OAKLAND, California - October 5 - A startling new study by the federal
Centers for Disease Control (CDC) says minute traces of a toxic rocket fuel
chemical found in milk, fruit vegetables and drinking water supplies
nationwide lowers essential thyroid hormones in women. An Environmental
Working Group (EWG) analysis finds that 44 million American women who are
pregnant, thyroid deficient or have low iodine levels are at heightened
risk from exposure to the chemical.

Regulators have known for years that perchlorate, the explosive component
of solid rocket fuel, can lower levels of the thyroid hormones essential to
proper development of fetuses and infants and good health in adults. But
new scientific evidence clearly shows that perchlorate is a much greater
public health threat than previously realized. Tests of almost 3,000 human
urine and breast milk samples — along with tests of more than 1,000
fruit, vegetable, cow's milk, beer, and wine samples — reveal that
perchlorate exposure in the population is pervasive.

The CDC's new study, released today, found that perchlorate exposure is
affecting thyroid hormone levels in American women, particularly those with
lower iodide intake. CDC researchers analyzed urine samples from more than
1,100 women for perchlorate, and then looked to see if perchlorate exposure
could predict thyroid hormone levels. They found a statistically
significant relationship between perchlorate levels as low as 3 parts per
billion — about one teaspoon of water in an Olympic-sized swimming pool
— and one type of thyroid hormone for all women, and an even more marked
relationship between perchlorate levels and two types of thyroid hormones
in women with lower iodine intake. Thirty-six percent of U.S. women have
iodine intake that falls into this category.

"The Pentagon and defense contractors, who are responsible for much of the
perchlorate in drinking water supplies, have lobbied hard against federal
standards, arguing that perchlorate posed no threat to healthy adults,"
said Renee Sharp, an EWG analyst who has studied the chemical since 2000.
"This new study shows that even very small levels of perchlorate in water
or food can have a marked effect on thyroid levels in women. We can't
ignore this serious public health issue any longer."

The median level of perchlorate in urine in CDC's study was just 2.9
micrograms per liter (a microgram per liter is equal to 1 ppb). Since
average urine output is about 1.5 liters per day, this means that women in
the study were ingesting somewhere around 5 micrograms of perchlorate per
day. Even at this low level, researchers found effects on thyroid hormone
levels. But the federal "safe dose" level corresponds to almost ten times
this dose. This clearly indicates that the current EPA reference dose and
cleanup guidance is several orders of magnitude too high.

EWG urges the federal government to act promptly to set a drinking water
standard of no more than 0.1 parts per billion of perchlorate — almost
250 times more stringent than the current federal recommendation for
cleanup of contaminated water, and 20 to 60 times stricter than drinking
water standards set by Massachusetts and pending in California and New
Jersey, the only states to take action so far. With new evidence showing
widespread food contamination and effects on the thyroid at typical
exposure levels, perchlorate exposure through drinking water cannot be
tolerated. EWG also urges the Food and Drug Administration (FDA) to
consider making the iodization of salt mandatory, because insufficient
iodide in your diet can compound perchlorate's health effects, and iodide
deficiency has increased sharply since the 1970s.

The vast majority of perchlorate manufactured in the United States is used
by the Department of Defense to make solid rocket and missile fuel, while
smaller amounts of perchlorate are also used to make firework and road
flares. Perchlorate is also a contaminant of certain types of fertilizer
that were widely used in the early part of the 20th century but are in
limited use today.

In July, Massachusetts set the nation's first drinking water standard for
perchlorate of 2 parts per billion, while California and New Jersey are
currently considering standards of 6 ppb and 5 ppb, respectively. The EPA
has yet to set a federal drinking water standard, but has issued a
controversial cleanup "guidance" level of 24.5 ppb. In March, a federal
advisory committee on children's health sharply criticized the agency,
writing in a letter to EPA Administrator Stephen Johnson that the guidance
was "not supported by the underlying science and can result in exposures
that pose neurodevelopmental risks in early life."

In 2003, EWG and the Riverside Press Enterprise independently tested
store-bought winter lettuce for perchlorate and found the contaminant in
more than half of the samples tested — in some cases at high levels. A
year later EWG tested California milk for perchlorate, finding the chemical
in 31 out of 32 samples. Around the same time, the California Department of
Food and Agriculture secretly conducted their own milk tests and found
perchlorate in all 32 samples collected. These studies were some of the
first indications that food might be an important route for perchlorate
exposure in addition to contaminated drinking water.

More than 1,000 tests by government and independent scientists later, there
can be no debate: The US population is being widely exposed to perchlorate,
both in water and in the food supply. Perchlorate is polluting water
supplies for millions of Americans. According to tests conducted under the
EPA's Unregulated Contaminant Monitoring Rule, 160 public water systems in
22 states are contaminated with perchlorate.

Perchlorate has also been found in a wide variety of domestic and imported
produce, with some of the highest levels being found in oranges, grapes,
raspberries, apricots, melons, lettuce, tomatoes, basil, kale, spinach and
asparagus. The chemical has also been found in 98 percent of 222 milk
samples collected from 22 US states, and in hundreds of samples of beer and
wine. Fruits and vegetables had the highest concentrations. Overall, 69
percent of the 1,090 food and beverage samples tested had detectable
perchlorate.

Tests by the CDC and independent researchers confirmed that many Americans
are carrying levels of perchlorate in their bodies well above the levels
found to lower thyroid levels. CDC sampled the urine of almost 3,000
Americans — a valid statistical sample of the entire population — and
found perchlorate in everyone at an average of 5.5 parts per billion. An
academic study of breast milk from 36 women in 18 states also found
perchlorate in everyone tested, with an average level of 10.4 ppb.