Story originally printed in the Winona Daily News or online at www.winonadailynews.com
Published - Friday, March 02, 2007
Health officials cut safe levels for 3M chemicals in groundwater
ST. PAUL — State health authorities on Thursday lowered what they consider to be safe levels of long-term exposure to two chemicals once manufactured by 3M Co. and now found in groundwater east of St. Paul.
The new guidelines apply to chemicals called PFOA and PFOS, both of which have been detected in south Washington County’s groundwater.
The changes won’t affect most residents in the Lake Elmo and Oakdale area who are hooked up to municipal water systems that either treat the water or don’t contain the chemicals, the Minnesota Health Department said in a release.
The agency is still studying data on another 3M chemical, PFBA, which was recently found in the groundwater in parts of southern Washington County and northern Dakota County.
The Health Department dropped its recommended safe level for PFOA from 1 part per billion to 0.5 ppb, and for PFOS from 0.6 ppb to 0.3 ppb. Daily, lifetime consumption of the chemicals at or below those levels poses little or no risk to human health, the release said.
3M made a class of chemicals called perfluorochemicals, or PFCs, at its Cottage Grove plant from the 1940s through 2002. They were used to make stain repellants, fire retardants and other products. PFOS and PFOA were detected two years ago in Oakdale and Lake Elmo’s water supplies, and 3M built a $2.5 million treatment facility to remove them from Oakdale’s water supply.
There’s no direct evidence linking the chemicals to human health problems, but high doses of the chemicals have been linked to liver and thyroid problems in laboratory animals.
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