Commercial infant food labelled as from organic and conventional origin (n = 87) was analysed for total mercury content using a direct mercury analyser (DMA). Median contents of mercury were 0.50, 0.50 and 0.40 μg kg⁻¹ for processed cereal-based food, infant formulae and baby foods, respectively, with a maximum value of 19.56 μg kg⁻¹ in a baby food containing fish. Processed cereal-based food samples showed statistically significant differences for mercury content between organic and conventional analysed products. Consumption of commercial infant food analysed did not pose a risk to infants when the provisionally tolerable weekly intake (PTWI) for food other than fish and shellfish was considered. By the contrary, a risk to some infants could not be excluded when using the PTWI for fish and shellfish. This is the first study reporting contents of total mercury in commercial infant food from both farming systems and the first on exposure assessment of children to mercury in Portugal.
Keywords: baby food; cereals; conventional production; infant formulae; mercury; organic production.