EVALUATION OF INTRA-INDIVIDUAL AND INTERINDIVIDUAL VARIATION OF URINARY 1-HYDROXYPYRENE, A BIOMARKER OF EXPOSURE TO POLYCYCLIC AROMATIC-HYDROCARBONS

The study was performed on 30, 8-year-old children living in an indust rial town of the Upper Silesia region. Morning urine samples were coll ected on 6 consecutive days. Intraindividual variation of urinary 1-hy droxypyrene concentrations, calculated as a coefficient of variance (C V), ranged from 14 to 109% whereas inter-individual variation ranged f rom 69 to 109%. Three-way analysis of variance disclosed a significant effect of sex, exposure to environmental tobacco smoke and day of exa mination on 1-hydroxypyrene concentrations not corrected for creatinin e. The appropriate sample size for population studies and the minimum number of observations for the individual assessment of environmental exposure to PAHs calculated on the basis of inter- and intraindividual variability of 1-hydroxypyrene concentrations in urine amounted to 16 4 and 99, respectively. Urinary 1-hydroxypyrene may be considered a go od indicator of environmental exposure to PAHs at the group level. (C) 1998 Elsevier Science B.V. All rights reserved.