Age and sex dependence of selected trace metals in scalp hair of urban population of Pakistan.

Concentrations of ten metals (Ag, Al, Cd, Cr, Cu, Fe, Mn, Sr, Ca and Mg) in scalp hair of urban donors from the city of Lahore, Pakistan were determined by the nitric acid/perchloric acid digestion based method by ICP-AES. The age and sex dependence of metal levels was investigated for the age groups 10-47 and 7-55 years, for females and males, respectively. In total 45 female and 42 male samples were analysed in triplicate. The maximum concentration in the male group was that of Fe, between 45 and 330 mg/kg, followed by Sr between 4.5 and 109 mg/kg. On average, the following order of metal concentration in male hair was observed: Ca > Mg > Fe > Sr > Al > Cu > Mn > Cr > Ag > Cd. For female samples Cu was found to have a maximum concentration (210 mg/kg) followed by Fe (170 mg/kg) and Sr (140 mg/kg). In this group the concentration order was: Ca > Mg > Cu > Fe > Sr > Al > Mn > Ag/Cr > Cd. A metal to metal correlation study showed that different metals were mutually correlated in male and female hair. Regression equations illustrated a distinct dependence of metal concentrations on the age of donors. The data are compared with corresponding data reported in the literature.