Interactions between essential and toxic elements in lead exposed children in Katowice, Poland

Objectives: To determine the influence of the essential element status on blood concentrations of lead and other toxic metals.

Design and methods: A group of 157 children from Katowice, an industrial area in Poland, was investigated for concentrations of lead and cadmium in whole blood, and mercury, selenium, zinc, copper, and magnesium in whole blood and serum. Relations between these elements, serum ferritin, hematological parameters, as well as serum selenoprotein P and glutathione peroxidase (GSH-px) were examined. Conversion factors for element concentrations (μmol to μg): lead 207.19, cadmium 112.41, mercury 200.59, selenium 78.96, magnesium 24.31, copper 63.55, and zinc 65.

Results: Blood lead was negatively associated with concentrations of selenium in whole blood and serum as well as selenoprotein P and glutathione peroxidase in serum. The association was mainly apparent at low blood lead concentrations, which may indicate an influence of selenium on the kinetics of lead, rather than an effect of lead on the selenium status. Children with low serum ferritin levels had statistically higher blood cadmium levels and a tendency for higher blood lead levels, indicating increased gastrointestinal absorption of these metals at reduced iron stores. Blood lead was negatively correlated with mean corpuscular hemoglobin concentration, which may reflect the effect of lead on hemoglobin synthesis. There was an association between blood mercury and selenium, indicating a common source of intake through fish consumption.

Conclusions: The results indicate that selenium and iron status may influence the kinetics of lead.