Table 1.

Characteristics of the study groups

Reference group (n = 49)Bitumen-exposed workers (n = 66)
Age (y), median (range)36 (19-61)40 (17-63)
Current smoking, n (%)20 (40.8)44 (66.7)
German nationality, n (%)44 (89.8)38 (57.6)
Duration of exposure (mo), median (interquartile range)084 (24-168)
Exposure to bitumen fumes and aerosols (mg/m3), median (interquartile range)5.3 (2.5-16.2)