Molybdenum Safety Levels Revised By State

State officials with the Department of Natural Resources have revised the advisory level for molybdenum, according to the Journal Sentinel.

The department conducted research on molybdenum health studies after a number of private wells in Kenosha, Milwaukee, Racine and Waukesha counties were found to have elevated levels of the element.

Molybdenum is a naturally occurring element in the earth’s crust and in water in low levels, but it’s also a byproduct of coal combustion and industrial waste. While humans already have trace amounts of molybdenum in their bodies, drinking water with high levels of molybdenum may carry some risk to humans including digestive problems and gout.

“After an extensive review of the scientific literature, we’ve concluded that molybdenum is a lesser health threat than originally understood and that the level in the water at which a health advisory is needed can be raised from 40 to 90 micrograms per liter and still be protective,” said Charles Warzecha, director of Environmental and Occupational Health at the Wisconsin Department of Health Services.

The interim health advisory level has been set at 90 micrograms per liter, which Warzecha says he's "confident this level fully protects public health.”

“These are important findings that provide residents in southeast Wisconsin with assurances about their family’s health and safety,” he says. “The good news is that three-quarters of the well test results we have received have been below the revised health advisory level.”

DNR, local officials and well owners first learned about elevated levels of molybdenum in a handful of private wells in the Oak Creek and Caledonia areas in August 2009.

An extensive DNR study completed this past January identified areas of southeast Wisconsin that have molybdenum levels above the state health advisory level but was unable to pinpoint a source or sources.

According to a press release from the DNR:
As of July 30, DNR has received results for 874 wells. Of that total, 469 wells, or 54 percent, had molybdenum levels equal to or below 40 micrograms per liter; 194 wells, or 22 percent, had molybdenum levels between 40 and 90; and 211 wells, or 24 percent, exceeded 90 micrograms per liter, the new health advisory level.
To learn more about molybdenum and to see a new map that shows what areas have been tested, please go to the DNR website.