Assessment of human inhalation exposure to polycyclic aromatic hydrocarbons.

The aim of the investigation was to find a suitable approach for assessing inhalation exposure of urban inhabitants to polycyclic aromatic hydrocarbons (PAHs) in air. Personal exposure to PAHs of fifteen subjects, Zagreb inhabitants, was measured over a week in summer and again in winter. All subjects kept a diary of motion and activities and filled in a questionnaire on the characteristics of their fiat and household members. PAHs concentrations inside and outside subject's homes were simultaneously measured as were those in the working environment and in transport. Using an exposure model which takes into account the time spent by the subjects in each microenvironment and the respective concentrations measured, the inhalation exposure of each subject was calculated and compared with the directly measured personal exposure for the winter season only the summer concentrations being negligible. For a few subjects the calculated inhalation exposure deviated considerably from the one measured directly. This could be attributed to the fact that the subject spent some time in a microenvironment with significantly different PAH levels which were not included in the calculation. However, if the average results for the whole group are considered, there was no statistically significant difference between the directly measured and calculated PAH inhalation exposures. Therefore the described approach could be used for calculating average inhalation exposure to PAHs of population groups with common characteristics.