Concentrations of Heavy Metals in Processed Baby Foods and Infant Formulas Worldwide: A Scoping Review

The aim of this study was to synthesize the global evidence of heavy metal (HM) concentrations in baby foods and infant formulas. The toxic HMs lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) have been detected in baby foods and infant formulas, raising health concerns. Advanced searches were performed. Baby foods were classified into 7 groups according to their primary ingredient. Infant formulas were classified as: Stage 1 (<6 months), stage 2 (6-12 months), stage 3 (>12-36 months), and specialty. Median concentrations and interquartile ranges were calculated for each classification. The percentage of items by category exceeding the International Maximum Levels (MLs) was obtained. Seventy-five studies were included in the scoping review, which in total examined 580 baby foods and 251 infant formulas. Pb, Cd, and As were detected in over 60% of baby foods. The highest Pb median was found in rice mixes and fish mixes (0.008 mg/kg each), with >20% of their items exceeding the Pb ML. The highest Cd median was found in cereals (0.013 mg/kg) and mixes of various foods (0.008 mg/kg), with >17% of their items exceeding the Cd ML. For As, the highest median was found in mixed fish (0.165 mg/kg) and rice mixes (0.048 mg/kg), with 89% and 30% of items exceeding the As ML, respectively. For infant formulas, Pb, Cd, and As were detected in >60% of items. The highest Pb median concentrations were found in stages 1 and 2 (0.015 mg/kg each), with >60% of their items exceeding the Pb MLs. For As, without-stage (0.052 mg/kg) had the highest median, with >71% of items exceeding the As ML. Fifteen studies reported the health risks related to intake of various foods: significant risks were identified for infants ≥6 months for rice products, and ≤12 months stage 1 and 2 formulas. This review highlights widespread HM presence in baby foods and infant formulas. Exceedances of the ML were particularly notable in rice products for infants >6 months and infant formulas for babies ≤12 months of age.