Fibrous asbestos, including chrysotile, amosite, and crocidolite, is a dangerous health hazard, but valuable for technical applications. The goal of workplace air monitoring, performed in the period 2000-2005, was to establish the differences in exposure to asbestos of construction workers. We demonstrated that the geometric mean of respirable fibres concentration at blocks of flats was 3-fold higher (p<0.01) than that at cooling towers (0.14 f./cm³ and 0.05 f./cm³, respectively). However, for total dust concentration the relationship was reversed. The geometric mean of the total dust concentration during work at a block of flats (1.9 mg/m³) compared with one during the removal of cooling towers (5.9 mg/m³) was significantly lower (p<0.01). The applicable hygiene standards for exposure to asbestos were exceeded in 93.0% (buildings) and 93.3% (cooling towers) results of measurements.