Lead, cadmium and zinc in hair samples: relationship with dietary habits and urban environment

This study was performed in order to analyze the relationships between hair zinc, lead, and cadmium with the kind of diet consumed (by recall of the diet consumed the previous 14 days), living area (urban or rural), tobacco smoking, and body mass index (BMI) among 419 individuals of the Canary Archipelago. Median values and interquartile range were 43 μg/g (18.50-132.50) for zinc, 4.09 μg/g (2.19-8.38) for lead, and 0.128 μg/g (0.05-0.30) for cadmium. We observed that hair zinc was markedly elevated among those consuming fish more frequently and, to a lesser amount, among those who consumed meat frequently, among those living in urban areas, and among those with BMI over 25 kg/m(2), keeping a significant relationship with BMI. Hair lead was also higher among fish consumers, showed a trend to higher values among inhabitants of urban areas, and was lower among obese individuals. Hair cadmium was higher among those who consumed less vegetables and fruits. By multivariate analysis, introducing the variables meat, fish, and vegetable consumption, urban/rural; sex; age; and BMI values, we observed that fish consumption (beta = 0.15) was the only variable independently associated to higher zinc levels; fish consumption (beta = 0.15) and meat consumption (beta = 0.17) were related to high cadmium levels, whereas meat consumption was significantly associated to higher hair lead levels (beta = 0.15). Therefore, we conclude that hair zinc, cadmium, and lead seem to depend more heavily on dietary habits than on tobacco consumption or living in rural or urban areas.