Estimation of dietary intake and content of lead and cadmium in infant cereals marketed in Spain
Lead and cadmium have become highly toxic metallic elements. There is an obvious toxicological impact of these elements on infants since their intestinal absorption is significantly higher than in adults, thus it is desirable to quantify lead and cadmium levels in commonly consumed infant foods. Zeeman background correction, transversely-heated graphite furnace atomic absorption spectrometry, was used to determine both the lead and cadmium content of 91 Spanish infant cereals. Cereals were assessed in terms of different types, cereal predominant in formulation and whether it was obtained organically or conventionally. Preliminary analysis revealed a noticeably higher content of lead and cadmium (median, Q1-Q3) in organic cereals (n = 17, Pb: 26.07; 21.36-51.63; Cd: 18.52; 16.56-28.50 mu g kg(-1)) in relation to conventional ones (n = 74, Pb: 10.78; 6.43-19.33; Cd: 7.12; 4.40-11.77 mu g kg(-1)). Three formulations exceeded European lead maximum levels. Added ingredients (milk, cocoa, fruit and honey) to the cereal base provide lead enrichment. For cadmium, this pattern was observed by cereal based on cocoa, but also the raw materials contributed with a dilution phenomenon, decreasing the final cadmium concentration in infant cereal. Apart from several organically produced cereals, lead content showed a narrow variation, where gluten-free cereals provide lower cadmium content than formulations containing gluten. Dietary intakes of both elements were assessed in comparison with the reference intake values proposed by the EFSA Panel on Contaminants in the Food Chain. Organic infant cereals based on honey and cocoa supplied the highest risk intakes of lead and cadmium, respectively. In accordance with the actual state of knowledge on lead and cadmium toxicity and attending to the upper limits calculated from risk intake values set by EFSA, it seems prudent to call for a revision of both heavy metals content regulated by EC to set a maximum guideline values for infant cereal at 55 and 45 mu g kg(-1), respectively.