Toxic risk assessment of selected metals in infant formula milk commercially available in Lebanon: A novel approach based on feeding parameters versus toxicity

Infant formula milk (IFM) is increasingly utilized as a substitute for natural breastfeeding despite the fact that breast milk has been always recognized as the optimal nourishment method. While IFMs are fortified with essential nutrients that are crucial for proper growth, they can also harbor non-essential toxic metal contaminants from various sources during the production process. Given the heightened vulnerability of newborns to such contaminants, it is imperative to thoroughly analyze, evaluate, and minimize the toxicity associated with the consumption of such IFMs. However, classical approaches to date, have been always adopted for assessing such risks by finding first the analytical concentration of metals in the IFMs followed by multiplying it by the average daily powder intake (ADI) then dividing by the average infant weight. The outcome is then compared to an established standard such a PTWI to assess the extent of toxicity. The drawback with such studies is the use of a fixed ADI for all samples as if all samples have the same and exact preparation directions while using somewhat different infant masses.

Accordingly, this study aims at assessing the toxic risk amongst newborns from IFM consumption through the identification and application of various highly important and toxicity-contributing parameters from each IFM and its directions of preparation label separately which are discussed here for the first time while providing comparisons between the classical approach versus our new approach to highlight its importance.

Seventy-three IFMs (0–6 months) were analyzed for lead (Pb), cadmium (Cd), arsenic (As), and aluminum (Al) levels and unlike previous studies, this work incorporated various feeding parameters from each IFM for calculating the intakes thus, revealing potential toxicity risks even in IFMs that are considered safe by the classical approach. Metal contamination was significant, with 97.3 % of samples containing detectable Pb, 41.1 % Cd, 16.4 % As, and 93.2 % Al while highlighting Pb in exceeding its maximum allowable level (MAL). This novel approach, which considers new diverse feeding schedules/parameters that are ironically suggested by manufacturers that have been previously overlooked elsewhere, emphasized IFMs' potential as sources of heightened metal toxicity in comparison to classical approaches. Results highlighted Pb and Al as major concerns, with As and Cd of lesser concern. Findings also emphasized the importance of such new parameters for safeguarding newborn health and should be payed attention to by caregivers. The study strongly and highly recommends adherence to minimum feeding schedules (MFS) and proper scooping techniques to reduce newborn exposure to toxic metals. It also suggests continuous monitoring and stricter regulations by health authorities at the production level of such products so as to provide a safer commodity in the first degree and to also provide better and somewhat uniform and specific feeding labels and precautions on such products.