Influence of Technological Housing Conditions on the Concentration of Airborne Dust in Dairy Farms in the Summer: A Case Study.

This research shows the size composition of airborne dust fractions in selected dairy barns down to the smallest particles, including factors that influence this composition. Measurements with a Dust-Track 8530 laser photometer took place in the summer at external temperatures of 29.5 to 36 °C. In barns with straw bedding, the average total dust concentration TDC was 66.98 ± 28.38 μg·m (PM 60.11 ± 19.93 μg·m, PM 49.48 ± 13.76 μg·m, PM 44.78 ± 10.18 μg·m, and PM 38.43 ± 9.29 μg·m). In barns without straw bedding, the average TDC was 55.91 ± 36.6 μg·m, PM 33.71 ± 13.86 μg·m, PM 30.69 ± 15.29 μg·m, PM 27.02 ± 13.38 μg·m, and PM 22.93 ± 10.48 μg·m. The largest TDC of 108.09 ± 32.93 μg·m (PM 69.80 ± 18.70 μg·m, PM 68.20 ± 18.41 μg·m, PM 53.27 ± 14.73 μg·m, and PM 38.46 ± 5.55 μg·m) was measured in an old cowshed with stanchion housing for 113 cows, straw bedding, and ventilation through windows. In a modern cowshed for loose housing of 440 lactating cows without straw bedding, with natural ventilation and 24 axial fans, TDC was 53.62 ± 49.52 μg·m, PM 20.91 ± 5.24 μg·m, PM 17.11 ± 3.23 μg·m, PM 13.71 ± 0.92 μg·m, and PM 12.69 ± 2.82 μg·m. In all investigated barns, a large proportion of airborne dust particles (54.38 ± 20.82% of TDC) consists of the smallest PM dust particles (from 12.69 ± 2.82 μg·m to 48.48 ± 1.18 μg·m).