Contaminants and Agricultural Production of Food for Human Consumption

Funder: U.S. Food and Drug Administration (FDA)

Status: Complete

Contract Start: September 2023

Project Description: The U.S. Food and Drug Administration’s (FDA’s) Closer to Zero initiative aims to reduce child exposure to four heavy metal contaminants found in food: arsenic, lead, cadmium, and mercury. The FDA prioritized these four heavy metals due to their relative toxicity, prevalence in the food supply, and the relative contribution of food as a source of exposure. To inform this work, the FDA, in collaboration with the U.S. Department of Agriculture (USDA), commissioned the Evidence Center to conduct a scoping review on agricultural production processes and arsenic, cadmium, lead, and mercury in foods for human consumption. The Evidence Center built an interactive evidence map that displays more than 10,000 articles included in the scoping review and allows users to sort and filter articles by food, production process category, and heavy metals of interest.

Research Question: What agricultural production processes are included in published research related to arsenic, cadmium, mercury, and lead in food for human consumption?

Approach: Scoping Review

Publication: An interactive tool to identify existing evidence and research gaps on agricultural production processes to address heavy metals in foods: developed from a scoping review. DOI: 10.1080/10408398.2026.2694487

Graphical Abstract:

Background:

• Agricultural production processes can introduce or reduce heavy metals in foods, which are taken up through soil, water, and air, often from pollution and other environmental sources.
• The FDA, in collaboration with USDA, commissioned the Evidence Center to conduct a scoping review on agricultural production processes and four heavy metals (arsenic, cadmium, lead, and mercury) in foods for human consumption.

Key Findings:

• More than 10,000 articles met the inclusion criteria.
• More than 600 foods and nearly 30 agricultural production process categories were included and organized into three food domains (crops, meat and poultry, and seafood), resulting in more than 18,000 food and production process pairs.
• Most articles assessed crops (73%), compared to seafood (21%) and meat and poultry (8%).
• Most articles assessed cadmium (68%) and lead (44%), compared to arsenic (24%) and mercury (15%).
• The Evidence Center built an interactive evidence map of more than 18,000 food and production process pairs. For each pair, the evidence map provides articles by the heavy metals assessed. The tool allows users to sort and filter by food, production process category, and heavy metals of interest.

Addressing Research Gaps:

• The evidence map enables researchers and decision-makers to identify high priority topics warranting systematic reviews where evidence is available, as well as opportunities for primary research where evidence is lacking, but concerns about heavy metal contamination exist.
• The amount of peer-reviewed evidence increased over the 10-year period covered by this scoping review, demonstrating a growing research base. Future funding to update the evidence map could capture emerging technologies in agricultural production processes in foods.

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