Concentration of heavy metals in UHT dairy milk available in the markets of São Luís, Brazil, and potential health risk to children

•First study gauging heavy metals and antagonist levels in Brazilian dairy products.•Principal heavy metals observed in dairy products of São Luís were Hg, Pb, and Ni.•Calcium (Ca), lead’s antagonist, was highly concentrated in dairy products. To assess the levels of heavy metals and their antagonists in dairy products available in the markets of São Luís, northeastern Brazil. Chemical analysis of the heavy metals copper(Cu), lead(Pb), mercury(Hg), and nickel(Ni) and their antagonists iron(Fe), zinc(Zn), calcium(Ca), selenium(Se), and cobalt(Co) contained in dairy products using inductively coupled plasma optical emission spectrometry (ICP-OES). The main heavy metal observed in dairy products were Hg; Pb; Se and Ni. A significant negative correlation was observed between the concentrations of Cu and Fe (rho = −0.634, p = 0.001), Cu and Zn (rho = −0.794, p = 0.000) in whole milk. A non-significant positive correlation was observed between Pb and Ca (rho = 0.387, p = 0.056), and Hg and Se (rho = 0.055, p = 0.795). Dairy product brands available in the markets of São Luís could be considered a source of heavy metal contamination (Hg, Pb, Se, Cu, Ni) with weak correlations with their antagonists.