Background: In this paper the exposure assessment to airborne biohazards (organic dust, microorganisms, endotoxins and ((1→3)-β-D-glucans) as well as to ammonia and hydrogen sulfide among CAFO (swine farms) workers is presented. Materials and Methods: Occupational exposure assessment was carried out on 30 swine farms. Personal dosimetry was carried out among 90 swine farm workers to assess the exposure to organic dust, endotoxins and glucans. Concentrations of ammonia and hydrogen sulfide were measured using Draeger pipes. Endotoxins were assayed with the LAL test in a kinetic, chromogenic version and ((1→3)-β-D-glucans with the Glucatell test in a kinetic version. Results: Concentrations of inhalable dust ranged from 0.16 to 37.2 mg/m3, with AM = 3.65 mg/m3, whereas AM for respirable fraction was 0.39 mg/m3 with the range from zero to 4.28 mg/m3. Mean concentration of culturable bacteria was 4.79×105 jtk/m3, and fungi concentration was ten times lower - 1.55×104 jtk/m3. Exposure to endotoxins with high degree of differentiation ranged from 95 to 147 885 EU/m3 in inhalable and from 5.5 to 18 708 EU/m3 in respirable fractions. Glucan concentrations ranged from 6 to > 5200 ng/m3 in unhalable and from 1 to 800 ng/m3 in respirable fraction. Ammonia concentrations in the workplace air ranged from 1.78 mg/m3 (2.50 ppm) to 30.1 mg/m3 (42.4 ppm). Hydrogen sulfide did not exceed the level of 4.1 mg/m3. Conclusion: Work conditions found in CAFOs may induce adverse effects on workers' respiratory system and should be considered as an important harmful agent. The protection of workers respiratory airways should be recommended. Med Pr 2010;61(3):257-269