Food Grown in Idaho Can Be High in Fluoride
Fluoride Contaminated Irrigation Water Absorbs into Some Foods
Foods grown in Idaho can contain dangerous levels of fluoride, according to an abstract to be presented at the 2009 National Environmental Public Health Conference on October 26, 2009 in Atlanta Georgia.
Many parts of Idaho have groundwater with naturally-occurring fluoride above the EPA's Maximum Contaminant Level (MCL) of 4 milligrams per liter - a level that if consumed daily leads to abnormal bone growth and
Private wells that serve fewer than 15 connections or 25 individuals are not subject to EPA drinking water standards, according to presenter Kai Elgethun. Thousands of wells in rural Idaho fall into this category.
Transient wells serving schools are also exempt from fluoride standards, he says. Irrigation wells are completely exempt despite the fact that crops can take up significant amounts of fluoride, he writes.
Foods raised using fluoride contaminated water may contribute appreciably to human exposure to fluoride.
"We evaluated the relative contribution of fluoride...affected produce to residents' total exposure in addition to water ingestion alone," writes Elgethun.
Fluoride levels in southwest Idaho drinking water wells that were at or over the MCL averaged around 7 milligrams per liter (range 4 mg/L - 22 mg/L).
Leafy greens can concentrate fluoride in their edible portions. Levels in these crops can add an additional ~5-20% to the total oral dose when compared to water ingestion alone.
Crop uptake and subsequent food ingestion should be considered when calculating total oral dose for water contaminants and when educating the public, Elgethun concludes.
Source: "Safe from the Tap?: Hazards in Drinking Water from Private and Municipal Wells,"