Lead levels in retail samples of Spanish infant formulae and their contribution to dietary intake of infants.

Lead concentrations in 82 different types of infant formulae (cow's milk and soy based) marked in Spain were analysed by acid-microwave decomposition and anodic stripping voltammetry. Dietary lead intake from infant formula and tap water used for powder formula reconstitution were estimated in comparison with the provisional tolerable weekly intake (PTWI). Additionally, the influence of physical state (powder and ready-to-use formulae), the type of container used and the impact of the industrial process from different manufacturers on lead levels were evaluated. According to the results, lead exposure from drinking water was negligible with respect to formulae investigated; where soya formulae contributed the highest intake (58-73% PTWI), non-adapted starter and specialized formulae gave an moderate intake (31-42 and 26-37% PTWI, respectively), and, finally, pre-term, adapted starter and follow-up formulae provided the lowest lead intake (22-25, 22-26 and 16-22% PTWI, respectively). Based on the current state of knowledge about lead toxicity, manufacturers are called to make an additional effort in order to keep a maximum lead level at 20 microg l-1 for all infant formulae, although it is recommendable that these formulations supply the upper limit (5 microg l-1) of 'normal' human milk.