LEAD CONCENTRATION IN SINGLE HAIRS AS A MONITOR OF OCCUPATIONAL LEAD-EXPOSURE

A rapid method for the analysis of 1-cm segments of single hairs has been developed. The hairs are washed with Freon TF in an ultrasonic bath and analyzed by electrothermal atomic absorption spectrometry. Due to diffusion of exogenous lead into the hairs the lead concentration increases along the hair shaft. Thus only the first 1-cm segment close to the hair root is used. In a reference population of 44 males no association was found between the hair lead concentration and age of the individual. Dark hairs tended to contain more lead than white hairs, but such difference was not apparent in occupationally exposed males. During four weeks blood and urine samples were collected from 87 males with occupational lead exposure, and hairs which had grown 1 cm during this period were then sampled and analyzed. The lead concentration in the first 1-cm segment of the hairs correlated significantly with the average lead concentration in blood and in urine, and δ-aminolevulinate in urine. Hair lead increases exponentially with increasing blood lead. A permissible limit of 60μg lead/100 ml blood corresponds to about 70μg lead/g hair or 3ng lead/cm hair. The analysis of single hairs for lead is recommended as a screening method. © 1978 Springer-Verlag.