Study: Rocket fuel chemical taints food, water
By Michael Coren
(CNN) -- There are few sure ways to avoid ingesting perchlorate, the chemical used in rocket fuel that researchers have detected in breast milk at levels five to eight times higher than those considered safe, experts say.
Studies by the Food and Drug Administration and the Environmental Protection Agency suggest that perchlorate enters the food supply through reservoirs and tainted irrigation water that contaminates crops and livestock.
The chemical has been found in store-bought produce, such as lettuce, in milk and in public drinking water supplies across the United States. More than 11 million people have some level of perchlorate in their drinking water, according to the National Research Council.
Perchlorate is used in explosives and as an ingredient in solid rocket fuel. Although found naturally in some areas, production of the chemical began in the mid-1940s by the U.S. military and aerospace industry, which accounts for 90 percent of its use, according to the EPA. Few consumer products contain the chemical, which is used in mortars, grenades, fireworks, lubricating oils and air bags.
A report by Texas Tech University researchers, published this week in the journal Environmental Science & Technology, tested breast milk of 36 women in 17 states. It found "measurable levels of perchlorate in every sample ... analyzed."
The study revealed "levels as high as 92 parts per billion (ppb), which expose infants to concentrations of the contaminant that are 20 times higher than the safe dose recently recommended by a National Academy of Sciences (NAS) committee."
"Our findings are very surprising because we found that perchlorate in breast milk is widespread, doesn't appear to come from drinking water, appears to suppress iodide in breast milk, and in some cases, the levels are really high," said Ph.D. student Andrea Kirk. Perchlorate can inhibit thyroid hormones and may cause iodine deficiencies that lead to learning disabilities or lower IQ.
The study found concentrations of perchlorate in breast milk averaged 10.5 micrograms per liter. Breast milk from two women in New Jersey showed the highest levels of perchlorate with nearly 92 micrograms per liter. The authors say this exposes many infants to a daily dose above that recommended by the NAS, about 0.7 microgram per kilogram of body weight.
"It is obvious that the NAS safe dose [for perchlorate] ... will be exceeded for the majority of infants," the report said.
Since different regions of the country growing produce may be contaminated, perchlorate-tainted produce may change seasonally. The chemical cannot be washed off and could be present in products such as manufactured beverages.
The EPA reports that wastes from the manufacture and improper disposal of perchlorate-containing chemicals are increasingly being discovered in soil and water. There have been confirmed perchlorate releases in at least 25 states, the agency said.
For pregnant women, doctors say iodine supplements should compensate for iodide deficiencies during pregnancy.
But Sandra Steingraber, biology professor at Ithaca College in New York, does not recommend switching infants to formula since breast milk is still the best source of sustenance for newborns.
"In my mind, the answer it is not to put babies back on formula which is inferior in my mind," said Steingraber. "It is to get the contaminants out of the environment in the first place and out of women's breasts."
Last week, the EPA adopted National Academy of Sciences recommendations for daily perchlorate exposure of 0.7 microgram per kilogram of body weight, known as a "reference dose" not expected to harm public health. A preliminary limit by the EPA set the bar much lower at 0.03 micrograms. The EPA claims the new dose still provides a "ten-fold uncertainty factor" to protect developing fetuses and newborns.
However, public interest groups insist the Texas Tech study means the standard falls far short of what is needed to protect public health and the agency must reconsider the standard. The EPA has said it is reviewing the study.
"This study showed that the majority of infants would exceed the safety standard just from exposure to rocket fuel in breast milk," said Richard Wiles of the Environmental Working Group, a watchdog organization. "We think this study will practically force the EPA to set a public standard for perchlorate rocket fuel that protects infants and children."
Acute perchlorate contamination in the U.S. occurs primarily around Air Force installations and manufacturing plants. Since it dissolves easily in water, it spreads rapidly in water supplies. About 20 million pounds of perchlorate are produced annually, according to the Environmental Working Group.
Perchlorate poses some health risks to adults despite being used to treat thyroid conditions in humans during the 1960s. However, the most serious risks from the chemical are magnified for children.