Contribution of fish consumption to heavy metals exposure in women of childbearing age from a Mediterranean country (Spain)

The concentrations of cadmium (Cd), lead (Pb) and mercury (Hg) were determined in samples from sword-fish (Xiphias gladius, n = 37) and louvar (Luvarus imperialis, n = 17) taken in an official surveillance programme in Madrid (Spain). The levels of heavy metals were measured by atomic absorption spectrophotometry (hydride generator for Hg and flame atomic absorption for Cd and Pb) after digestion of the samples (microwave digestion for Hg and drying chamber for Cd and Pb). Pb contamination was negligible in both species. Cd was detected in 89.19% of the samples from sword-fish and 52.94% from louver; 17.65% of louvar and none from sword-fish being higher than maximum residue limits (MRL). However, around 90% of louvar samples and around 35% of sword-fish portions exceeded MRL for Hg; around 30% of louvar samples having levels even higher than 1 μg/g. The consumption of one serving of 150 g either of louvar or sword-fish would not be relevant for Cd and Pb provisional tolerable weekly intake (PTWI) of these elements for women in childbearing age, but it would largely exceed the tolerable values for Hg.