Why Are There Heavy Metals in My Food?
Earlier this month, a subcommittee of the U.S. House of Representatives Committee on Oversight and Reform released a staff report that confirmed several baby food companies had knowingly used food ingredients that contained “high” levels of toxic heavy metals in their products. The Subcommittee on Economic and Consumer Policy requested internal documents and test results from seven of the largest manufacturers of baby food in the United States in November 2019 following reports of alleged high levels of heavy metals. Four of those companies responded.
This report led to many media stories alerting the public to this food issue. Arsenic, lead, cadmium, and mercury in varying levels were found in either the ingredients or the finished product, if the test had been performed. The primary concern was that some of the results were multiple times higher than what the Food and Drug Administration allows for drinking water.
Aside from drinking water, the FDA has set only one standard in baby food products. Infant rice cereal may not exceed 100 parts per billion of arsenic. Since no other standards exist, companies may set internal standards for different products. Heavy metal amounts may vary depending upon how they will be mixed/diluted with other ingredients for the final product. Additional concern came from the fact that there were instances the responding companies used ingredients that exceeded their own internal standards.
While farmers have no control on what happens to ingredients once they leave the farm, EngAGe Kentucky, a food production education program of the Kentucky Agriculture and Environment in the Classroom and the Kentucky Livestock Coalition, wanted to shed light on how heavy metals may enter foods as they are being grown and how it may be controlled. We talked with Dr. Mark Coyne, professor of plant and soil sciences and soil microbiology specialist, at the University of Kentucky to learn more.
What is the source of heavy metals?
Heavy metals naturally occur in our environment and they enter our food supply because plants take them up as they grow.
According to Coyne, heavy metals can also build over time in food production systems from certain soil amendments. He said phosphorus fertilizers that are produced from rock, typically contain cadmium.
Coyne also explained that soil amendments, such as animal waste and biosolids from wastewater treatment, may have high levels of heavy metals as well. Nutrition supplements and metals in both animal feed and human diets are often secreted from the body. Municipal waste can have additional heavy metal levels because they are mixed with untreated water runoff from streets. Engine oils and metal residues from automobiles and other equipment can easily add to heavy metal content.
Another factor reported by the Food and Drug Administration was chemical residue from industrial mining and manufacturing can enter soils and water.
Can heavy metals be reduced in foods?
Coyne said that regulation and testing for heavy metals can be done at both the farm and the processing plant, but it is ultimately up to the food manufacturer to manage the farm-to-product process.
“Companies can ensure that their food ingredients are being grown in soils with a minimum concentration of heavy metals,” explained Coyne. “In Kentucky, an advanced soil test for heavy metals can be requested. If levels are high, the issue can be addressed by growing those ingredients in a different location.”
According to the Hazardous Substance Research Center, other methods of reducing heavy metals include physical removal of the soil, stabilization of the heavy metals through chemical means so it is much less harmful, or by using plants to extract the heavy metals. This last method is known as phytoremediation. It is the most cost efficient method but may take several years.
Coyne said farmers can have some control of addressing heavy metal contamination by requesting the more advanced soil tests and learning what they can about the soil amendments they use. Fertilizer and soil amendment companies may test their products for heavy metal content and having a trusted supplier of those products may be a good practice.
Food purchasing and consumption decisions can also be important. Since rice cereals have historically had higher arsenic levels since it absorbs it more readily than other crops, Gerber suggests on their website that parents provide their babies and children a varied diet to reduce overall exposure. They stress that this issue is not limited to commercial foods. Heavy metals may be present in food ingredients that are also grown organically and in backyard gardens.
An extension publication from Oregon State University specifically addressed how to control lead in produce, reporting that high concentrations would be limited to surfaces of leafy vegetables and root crops from soil residue. They said that growers should always wash their leafy vegetables, and consumers should always wash their produce before eating or cooking.
In providing specific information for safer practices, it is important to note that not all plants and food crops absorb heavy metals in the same way.
How will heavy metals be regulated in the future?
Heavy metal presence in baby foods is of particular concern because of their effects on babies and children. Due to the subcommittee’s findings, they have made the following recommendations:
Require mandatory testing of finished baby food for toxic heavy metals.
Require manufacturers to report levels of toxic heavy metals on food labels.
Ask manufacturers to find substitutes for ingredients or phase out products that frequently test high for toxic heavy metals.
FDA should set maximum levels of toxic heavy metals permitted in baby foods.
Parents/caregivers should avoid baby foods that contain ingredients testing high in toxic heavy metals. Instituting the first four recommendations will give parents the information they need to make informed decisions.
What are your thoughts?
In attempt to simplify the aspects of this issue, there is no doubt heavy metals in the food supply is complex. In class or with your peers discuss the issues and list other questions you have. Do you agree with the regulations presented? What additional information do you think is needed for regulations to be created? Which entities should be responsible for solving the problem?
Additional reading resources:
Metals and Your Food (FDA)
What FDA is Doing to Protect Consumers from Toxic Metals in Foods (FDA)
Arsenic (Collaborative on Health and the Environment)
Cadmium in Fertilizer (Pollution Prevention Resource Center)
Arsenic in Chicken: Does chicken meat contain arsenic? Are chickens fed arsenic? (National Chicken Council)