Molybdenum is a metallic element that is naturally present, usually at low levels, in the earth’s crust. Trace amounts of molybdenum are necessary for human health, and are obtained from common foods in the diet such as leafy vegetables, legumes, grains and organ meats. Higher concentrations have been found in soil or groundwater and sometimes...tap water (yikes!)
Typically this is in conjunction with spills or some historic waste disposal practices. Residents are advised to avoid the extremely low risk associated with future molybdenum exposures by not consuming water that contains molybdenum above the health advisory level of 90 micrograms per liter (μg/L). Naturally-occurring levels of molybdenum in groundwater are low; U.S. Geologic Survey found a median value of 1 μg/L nationwide. Most well owners do not need to include molybdenum during annual well testing. Right now, no national drinking water standard exists for Molybdenum, which means it is not tested for on a regular basis.
Molybdenum is not regulated in public drinking water supplies. However, the DNR does have a groundwater quality enforcement standard for molybdenum of 40 μg/L, based on the US Environmental Protection Agency’s (EPA) Lifetime Health Advisory (LHA). The EPA is currently reviewing their LHA level for molybdenum in drinking water. In 2013, the Wisconsin Department of Health Services (DHS) conducted a review of the scientific literature on molybdenum and determined that for individual well owners their health will not be affected by drinking water with molybdenum at levels up to 90 μg/L. Until the EPA completes its LHA review, the state will use an interim health advisory level for molybdenum of 90 μg/L for
individual drinking water advisories. People who ingest large amounts can have increased levels of uric acid and gout-like symptoms.
See all of our testing for heavy metals here.