Evaluation of heavy metals contamination in preterm human milk and infant formula: Occurrence and risk assessment

Exposure to heavy metals in infant formula and human milk can have serious health implications for infants, particularly preterm babies. This study compared the occurrence of arsenic (As), cadmium (Cd), and lead (Pb) in preterm human milk, infant formula, and water used for reconstituting formulas in Qatar, alongside a related health risk assessment. Forty-two human milk samples from lactating mothers of preterm infants at WWRC, Hamad Medical Corporation, were collected. Exposure was assessed in expressed human milk, considering potential contributions from pumping, storage, and feeding equipment. Additionally, 42 samples of preterm and term infant formulas from local markets and pharmacies and 10 samples of commonly available bottled water brands were analyzed according to European Union and WHO standards. Results showed that 26% and 19% of infant formula samples exceeded maximum limits for As and Pb, respectively, while 7% of human milk samples exceeded limits for As, and none exceeded Pb limits. Cd levels were within acceptable limits in all samples. Water significantly contributed (P < 0.05) to elevated As and Pb in reconstituted formulas. The health index (HI) exceeded 1, and total cancer risk (TCR) surpassed 10(-)(4) for both formula and human milk. Findings underscore the urgent need for stricter monitoring of bottled water and infant formula to protect vulnerable populations, especially preterm infants.