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During the 2025 Informational Session “Nonessential Heavy Metals in Food: How Low Should We Go?,” speakers Brinda Mahadevan, Wallace Hayes, Brenna Flannery, and Peter Pressman shared their insights about the ubiquitous presence of heavy metals in our environment impacting our food chain, covering the related health considerations along with exciting new and current risk management approaches to reduce dietary exposure. 

Humans require varying amounts of essential metals, such as manganese, magnesium, iron, copper, chromium, molybdenum, zinc, and cobalt, as they are essential for the maintenance of normal biological function, supporting numerous biological processes in our body.   

However, for nonessential heavy metals, such as arsenic, cadmium, lead, and mercury, the intent is to minimize the levels as much as possible as their presence in food can particularly be harmful for vulnerable populations, such as infants, individuals during pregnancy, and people with chronic health conditions. For some of those elements, animal data have shown carcinogenic, mutagenic, and teratogenic potential. Human data indicate neurodevelopmental as well as cognitive impairment and immunomodulatory effects potentially linked with noncommunicable disease development.  

The low-level occurrence in foods is, however, unavoidable because these elements occur naturally in the earth crust and are also the result of anthropogenic activity, resulting in their presence in all environmental compartments (air, water, and soil). They enter the food supply chain through the uptake by food crops, such as leafy and non-leafy vegetables, and bioaccumulation in animals, such as livestock and fish. In addition, their presence in the soil impacts the nutritional composition in plants competing with the uptake of essential metals, leading to nutritional deficiency in contaminated regions (B. Mahadevan and P. Pressman).  

Although the levels of these metals in different food commodities are low, the overall exposure adds up because many of the foods consumed contain them in small amounts. At a global level, different international regulatory bodies have established variable limits for these chemical components in food as part of food contamination control programs. Risk-Based approaches focusing on the protection of the most vulnerable populations are being considered, and as far as possible, safe (interim) exposure limits are derived as demonstrated by the US FDA Closer to Zero program currently for lead and cadmium (B. Flannery). However, meeting these limits is becoming a challenge because of the ubiquitous presence of these metals in the environment.  

In the search for other ways to reduce heavy metals at the source level, “derisking” approaches are being developed. To lower the levels of these contaminants, different solutions are being investigated, such as: 

The first results of these different mitigation options appear promising (W. Hayes). 

This blog reports on the Informational Session titled “Nonessential Heavy Metals in Food: How Low Should We Go?” that was held during the 2025 SOT Annual Meeting and ToxExpo. An on-demand recording of this session is available for meeting registrants on the SOT Online Planner and SOT Event App. 

This blog was prepared by an SOT Reporter and represents the views of the author. SOT Reporters are SOT members who volunteer to write about sessions and events in which they participate during the SOT Annual Meeting and ToxExpo. SOT does not propose or endorse any position by posting this article. If you are interested in participating in the SOT Reporter program in the future, please email SOT Headquarters.