"We know it can be harmful, but what the EPA is trying to determine is, how much is too much, and at what level are people affected?" said Zoeller.
Concern centers around the potential effects on the thyroid gland from exposure to perchlorate in the environment, specifically in drinking water. Perchlorate is both a naturally occurring and manufactured chemical, and is used as a propellant for airbags as well as in rocket fuel, Zoeller says. Wastes from the manufacture and disposal of perchlorate-containing chemicals are increasingly being discovered in soil and water, according to the EPA. Although pockets of perchlorate have been found in 20 states including in Massachusetts, on Cape Cod the preponderance of contamination has been found in the western United States, in areas of Nevada and California.
And, because water is believed to be the primary source of the contaminant, it's extremely difficult to determine how much is safe within a given water supply. "There are so many variables," explained Zoeller. "How much tap water do you drink? Do you cook your food in this water? Is the danger level for a grown man the same as for an infant who is nursing and who weighs 15 pounds?" Perchlorate doesn't build up within the human body, Zoeller notes, although it may in plants including vegetables that are irrigated with contaminated water. He notes that scientists do not believe that perchlorates are overtly toxic; that is, "it's not going to give you cancer or a liver problem."
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Contact: Elizabeth Luciano
luciano@journ.umass.edu
413-545-0444
University of Massachusetts at Amherst
10-Jul-2002