Molybdenum

What is molybdenum?

Molybdenum is a naturally occurring metal that is found in small amounts in soil, rocks, and water. Small amounts of molybdenum are used to process proteins and genetic material and break down toxic substances and unwanted substances that enter the body.

Molybdenum is used to make cast iron, stainless steel, biofuels, solar panels, and some industrial chemicals.

How can I be exposed to molybdenum?

People can be exposed to molybdenum from air, drinking water, food, and soil.

Air

People can be exposed to low levels of manganese in air from factories that use or make products with molybdenum and near mines and milling operations where molybdenum is sourced.

Drinking water

People can be exposed to molybdenum from drinking water as molybdenum is naturally present in Wisconsin's groundwater. High levels of molybdenum can also be found in drinking water near sites of environmental contamination.

Food

Low levels of molybdenum can be found in some foods. Foods that contain the highest amounts of molybdenum includes beans, whole grains, dairy products, and meats.

Soil

People swallow small amounts of soil each day with kids generally swallowing more than adults. Soil naturally contain small levels of molybdenum, but can contain higher levels if there are near sites of environmental contamination.

How can molybdenum affect my health?

While low levels of molybdenum are required to maintain health, high levels may cause health effects. Studies have shown that breathing air with high levels of molybdenum can damage the inside of the nose and increase the risk of cause lung cancer. Studies have also shown that swallowing large amounts of molybdenum can affect the kidneys and liver and impact reproduction and development.

How can I protect myself from molybdenum?

The highest exposures to molybdenum in Wisconsin come from private well water. Private well users should test for molybdenum if they live in certain parts of southeast Wisconsin.

• Test using a Wisconsin certified lab (PDF).
  • Households with pregnant people or a young child may be eligible for free testing. Check with your local health department to learn more.
• If the molybdenum level is equal to or greater than 90 micrograms per liter (PDF) (µg/L), retest your well to verify to results.
• If the molybdenum level is still high:
  • Everyone should use an alternative source of water for drinking and preparing foods that take up a lot of water.
  • Work to find a long-term solution. Options include installing a certified treatment device and drilling a new well.
    • Our Water Treatment Devices for Private Well Contaminants fact sheet, P-45012 (PDF) has information on common certified treatment devices and instructions for how to find them.
    • The DNR well compensation grants provide funds to address public health hazards in private wells.

Who regulates molybdenum in Wisconsin?

The Wisconsin Department of Natural Resources (DNR) regulates how much molybdenum can be released into air and groundwater in Wisconsin.

Related topics

• Our groundwater standards page has information on how Wisconsin's groundwater standards are set, DHS' role in the process, and a summary of the current and recommended standards including molybdenum.
• The DNR's molybdenum in groundwater page has information on molybdenum sources in Wisconsin's groundwater, recommendations on who should test their private wells for molybdenum, and details on treatment devices certified to remove molybdenum from drinking water.
• The Agency for Toxic Substances and Disease Registry's (ATSDR's) ToxFAQs page has more information on exposure routes and health effects of molybdenum.