In the submitted paper we compared the concentrations of individual and total polycyclic aromatic hydrocarbons (PAH) in the atmosphere of areas with different levels of pollution during winter and summer periods. At the same time we verified whether urinary 1-hydroxypyrene (1-OHP) - an assumed biological marker - permits the assessment of spatial and temporal variations in environmental PAH exposure. For our epidemiological study we used three groups of volunteers. The first group was formed by 22 physical training students from the first year of the Pedagogical University (PF VŠP) in Hradec Králové, who regularly train outdoors. During our study they spent 7 days in winter and 7 days in summer in a recreation area of Orlické hory. The control groups were formed by 22 girls from the fourth grade of a secondary school in Hradec Králové - residents of the town and by 18 residents from the mountains, age matched with the students. Analysis revealed total PAH concentration (sum of 13 individual PAH) 104.6 and 19.3 ng/ m 3 in Hradec Králové and in the Mountains, respectivedly, during summer and 261 and 86.6 ng/ m 3 during winter. Median 1-OHP levels ranged between 0.03 and 0.13 mmol/mol creatinine for controls and between 0.04 and 0.12 mmol/mol creatinine for the observed goroup of students. We did not find any relationship between pyrene levels in the atmosphere and group means of urinary 1-OHP. Base on our results we suppose that other factors (probably the content of PAH in food) mask the pollution influence on urinary 1-OHP levels in subjects exposed to PAH.

        Key words: environmental exposure - polycyclic aromatic hydrocarbons - envi- ronmental monitoring - biological monitoring