TRACE-ELEMENT CONCENTRATIONS IN BLOOD AND HAIR OF YOUNG APPRENTICES OF A TECHNICAL-PROFESSIONAL SCHOOL

The concentrations of total Fe, Cu, Mn, Zn, Pb, Cr, Ni and Ca in the w hole blood of young male apprentices of a technical-professional schoo l, who are exposed to low doses of fumes from manual metal are welding of mild steel, were monitored over their 2 years of apprenticeship in order to evaluate the influence of occupational exposure on biologica l metal levels. The results were compared with those from a control gr oup of the same sex and age and living in the same geographic area. Fo r comparison, monitoring of the same metal levels in the hair of both groups of individuals were also carried out. In the apprentices, the m ean metal concentrations in blood at the end of the study were statist ically significantly higher for Cu, lower for Fe and Mn and similar fo r the remaining metals. The levels of Fe significantly decreased where as the levels of Cu were significantly increased during the study. A s ystematic influence of the exposure period on the levels of Mn was not observed. All the metal concentrations measured in the blood and hair of both apprentices and controls fell in the very large range of publ ished reference levels. Seasonal variation (higher levels in the summe r) of the hair metal concentrations were observed for Mn, Cu, Pb, Ni, Zn and Ca. (C) 1997 Elsevier Science B.V.