Good food provides the many essential nutrients and other healthful components needed to grow and maintain health throughout a long and full life. However, it can be challenging to ensure the food is safe.

Food safety often focuses on avoiding harmful microorganisms in food that can make you sick very quickly. But a less obvious concern is minimizing the consumption of toxic heavy metals that find their way into food in various ways. These heavy metals include arsenic, lead, cadmium and mercury that can accumulate in the body over time and eventually have a serious impact on health.

Unfortunately, both conventional and organically grown food contains toxic heavy metals. Identifying the full extent of farm-to-fork food safety problems is complex but necessary to find appropriate solutions to producing safer food regardless of growing methods.

Infants and children are those most vulnerable to heavy-metal issues. They include irreversible brain development issues and increased risks of cancer and diabetes. Symptoms related to heavy-metal toxicity develop slowly, making it difficult to connect these health problems and heavy-metal consumption over time.

Question: Is there growing concern about heavy metal toxicity from foods?

Answer: Recently, a U.S. House of Representatives staff report revealed that voluntary data from four companies — Beech-Nut, Gerber, Nurture and Hain — indicated that many ingredients and finished baby food products contained significant amounts of heavy metals. However, Walmart, Campbell and Sprout Organic Foods refused to provide needed heavy metals data for the House subcommittee’s baby food investigation.

Company data obtained indicated that numerous ingredients and products contained varying levels of heavy metals. Rice and rice products, however, were identified as having the greatest arsenic levels in infant food. These levels indicate that it would be prudent to limit rice and rice product consumption for infants and young children.

Q: What is causing heavy-metal contamination of foods?

A: The concentration of heavy metals in plants depends on the amount of metal in the natural soil and water used for growing the plants. Also, some plant species have more affinity to take up one or more heavy metals. Industrial and agricultural activities can affect nearby soil, water and air and eventually make it up the food chain into some animal food.

Q: What can help limit dietary intake of heavy metals?

A: Health risks are dependent on both the actual metal level in food and the amount of food consumed over time. Heavy-metal levels vary by growing location. Since you can’t see heavy-metal contamination in food, consuming a wide variety of food from various locations can help minimize risk. Additionally, it is time to encourage food companies, the Food and Drug Administration and the Environmental Protection Agency to adopt existing international standards to control the amount of heavy metals in food.

Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Dobbs also works with University Health Services.