What Happened
FDA scientists published earlier this month an updated estimate of dietary intake of lead and cadmium by two groups: 1) young children (those aged 1 to 6 years of age inclusive); and 2) infants excluding those fed human milk—about half of the infants aged 0 to 11 months. While the results are similar to a 2019 study, this latest study used an improved methodology to evaluate data on food consumption from 2015–18 and food analysis for toxic elements from 2018–20.
Lead: One in ten children in each age group consumed at least 2.4 microgram of lead per day (µg/day), exceeding FDA’s current interim reference level (IRL) of 2.2 µg/day.1 This means that more than 2.6 million children exceeded FDA’s target—a target designed to keep their dietary contribution of lead to less than 0.35 µg/deciliter (µg/dL) of blood or 1/10th of CDC’s Blood Lead Reference Value. FDA acknowledges “there is no known safe level of exposure to lead” and has a Closer to Zero program designed to iteratively reduce the exposure.
For young children, grains and baked foods were the largest contributor at 25% of total mean exposure. Dairy and fruit were next at 13% and 12% respectively. Processed baby food contributes only 1.5%.
Not surprisingly, for infants fed no human milk, processed baby food and infant formula were the sources of 81% of their total dietary intake of lead. FDA plans to establish action levels for processed baby food in December 2024 and fruit juices in 2025.
Of the 307 types of food FDA evaluated, baking powder topped the list at 164 parts per billion (ppb) followed by cocoa powder at 63 ppb, though both were a single sample. Third was baby food sweet potatoes at 21 ppb with teething biscuits close behind at 18 ppb, both are based on eight samples.
Cadmium: The situation is much worse for cadmium than for lead; more than half of young children between 1 and 6 years of age—more than 12 million children—exceed the level that FDA considers protective of their health, called a toxicological reference value, or TRV.
FDA’s TRV for cadmium, set last year, is a range of values from 0.21 to 0.36 micrograms of cadmium per kilogram of body weight per day.2 It is designed to limit the bioaccumulation of cadmium in people over their lives to levels unlikely to harm their kidneys and bones by age 50. The agency said it did not identify sufficient data to establish a TRV for cardiovascular, developmental, and neurotoxicity impacts.
Using the midpoint of the range for simplicity, for young children aged 1 to 6, their mean exposure was 51% greater than the TRV and the 90th percentile was 150% greater. Infants not fed human milk had lower dietary exposure, but the 90th percentile was still 37% higher than the TRV.
For young children, grains and baked foods were the largest contributor at 42% of total mean exposure. Vegetables were second at 32%. Processed baby food contributes only 0.5%.
For infants fed no human milk, processed baby food and infant formula was the source of 55% of their total dietary intake of lead, followed by vegetables and grains/baked goods at 19% and 18% respectively. As part of its Closer to Zero program, FDA plans to propose an action level for cadmium (and inorganic arsenic), in December 2024 and finalize them a year later.
The highest levels of cadmium contamination were in cocoa powder where a single sample had 400 ppb. Sunflower seeds were second at 333 ppb, followed by spinach at 222 ppb, and potato chips at 130 ppb. The spinach number is particularly trustworthy because it was based on 27 samples, compared to 3 for sunflower seeds and potato chips.
Why it Matters
Estimating the dietary intake of lead and cadmium are important milestones in FDA’s effort to establish action levels for infants and young toddlers. They provide insight into how much of an overall reduction is needed to reach the agency’s targets and into the relative contribution of various types of foods.
Our Take
The study reinforces the need for FDA to take swift action to reduce lead and cadmium contamination in foods. Additionally, that action needs to go beyond foods marketed as baby food.
Lead: More than 2.6 million infants and young children exceed the FDA’s target for lead on any given day; far too many given the known risks lead poses to their developing brains. Though the individual children consuming these levels vary with time, lead is easily absorbed by their fast-growing bodies and quickly accumulates to levels over 0.35 µg/dL. Guidance to vary the diet has limited benefits for young children who want to eat the same foods—and often the same brands—day in and day out.
We are hopeful that FDA’s final action levels on processed baby food in December and on fruit juices a year later will help. However, its proposals, despite being the most protective in the world, were designed to avoid disrupting more than 10% of a food type, which may be too little to ensure significant reductions in children’s dietary intake of lead. FDA did not conduct a rigorous evaluation of what is achievable or the societal benefits of tighter standards.
Cadmium: More than 12 million young children exceed the agency’s safe dietary intake of cadmium. While it may be reassuring that the safe level is based on a lifetime buildup of cadmium in the body, California, in 2001, set a maximum allowable daily level (MADL) for Proposition 65 that is three times lower than FDA’s TRV based on developmental toxicity while also finding reproductive impacts are slightly higher levels.
Given the greater number of children at risk, we would expect FDA’s proposed action level for cadmium will go further than for lead, especially since the agency has identified best practices to reduce contamination. First and foremost, among those practices is avoiding phosphate fertilizers that are often contaminated with cadmium. Other practices include avoiding galvanized steel and reducing cadmium-bearing pottery glazes and stabilizers in plastics—practices that can also reduce lead contamination. FDA also should consider a recent study, Seyfferth et al., 2024, showing that reducing chloride content in soil and avoiding chloride based disinfectants may help for spinach.
Baby Food Insufficient: The action levels that FDA is planning to issue for food intended for infants and young toddlers will have little impact on children aged 1 to 6. According to the study, these children get less than 1.5% of the dietary intake for lead and cadmium from the foods. This new study makes clear that FDA needed to act more quickly on other foods that young children commonly eat.
Next Steps
We are looking forward to seeing how FDA uses its exposure study to set strong action levels for lead and cadmium by December 2024.
- We use the hybrid method as the best estimate for lead exposure. Under this method, FDA set values for foods with no history of detections (using data from Total Diet Study collections 2013–2020) to zero and set non-detected values for foods in the same dataset that have one or more detected values to half the Reporting Level. This is based on Xue et al. 2010. The issue is important for lead where 86% of the samples had no detectable levels and 63% of the 307 food types had no detections from 2013-2020. The issue was less important for cadmium levels 39% of the samples had no detectable levels and 30% of the 307 food types had no detections from 2013-2020. ↩︎
- The range of values considers various factors (i.e., age, sex, and body weight) that ultimately affect the estimate of daily cadmium exposure. ↩︎