The analysis of Pb-204, Pb-206, Pb-207 and Pb-208 isotope ratios for environmental Pb markers (leaded gasoline, air-borne particulate matter, house window dust) and hair of children was undertaken by the routine quadrupole inductively coupled argon plasma mass spectrometry (Q-ICP-MS). Hair samples collected from 10-year-old children living in Krakow in 1995 and 35 randomly selected children, aged 11, both sexes were included in the current study. Air-borne particles were collected by PM-2.5 (an aerodynamic diameter dac < 2.5 <mu>m) and PM-10 (fraction with an dac < 10 <mu>m) samplers in the proximity of steel factories situated near Krakow. Imprecision of routine estimations was approximately 0.6-0.7% or less, and was the lowest for the Pb-207/Pb-208 ratio (approx. 0.2%). These conditions were sufficient to distinguish Pb from air-borne dust from that in gasoline or window dust. No differences were found between Pb in PM-2.5 and PM-10 particles. The associations of the Pb in the these environmental sources and that in hair of children were discussed. The relationships of the Pb isotope ratios and other parameters related to environmental pollution were also analyzed. The analysis of distribution of the (207)Ppb/Pb-208 ratio in the hair of children, provided some evidence of the fact that hair lead of approximately 20% of the investigated population could arise from gasoline, while the Ph from air-borne dust and remaining sources can be attributed to approximately 80% of the population. (C) 2000 Elsevier Science B.V. All rights reserved.