D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria.
Agricultural Research and Education Center Raumberg Gumpenstein, 8952 Irdning, Austria.
Int J Environ Res Public Health. 2020 Dec 21;17(24):9572. doi: 10.3390/ijerph17249572.
Particulate air components can be of anthropogenic or natural origin. It is assumed that in different geographical areas varying concentrations of mesophilic bacteria are present in the ambient air. The aim of this study was to determine the background concentrations of airborne culturable mesophilic bacteria and particulate matter in the ambient air. Furthermore, the association between their concentrations and some environmental factors was analysed. In the period from July to October 2019, concentrations of mesophilic bacteria and dust particles were measured in urban, rural and mountain areas using the single-stage air sampler and the particle counter. The concentrations of bacteria and dust particles in the air were counted as number of Colony Forming Units per cubic metre (CFU/m) and particles per cubic metre (pa/m). sp. were identified. The median values of the cultivated mesophilic bacteria at 30 °C and 37 °C were 7.1 × 10 CFU/m and 2.3 × 10 CFU/m in mountain regions, 1.3 × 10 CFU/m and 6.9 × 10 CFU/m in rural regions and 2.1 × 10 CFU/m and 6.5 × 10 CFU/m in urban regions. The median of sp. was 2.5 × 10 CFU/m in alpine areas and 7.5 × 10 CFU/m in urban and rural areas. Higher bacterial concentrations were measured in sunshine and in windy weather. A relationship was observed between the concentrations of airborne mesophilic bacteria and the coarse particles in all three areas. The present study determined values between 5.0 × 10 and 4.6 × 10 CFU/m as natural background concentrations of airborne mesophilic bacteria and 1.2 × 10 pa/m and 6.5 × 10 pa/m for fine and coarse particles, respectively. These results can be proposed as baseline for the assessment of the emission sources of mesophilic bacteria for summer and early autumn.
空气中的颗粒物可能来自人为或自然来源。据推测，在不同的地理区域，环境空气中存在不同浓度的中温需氧细菌。本研究旨在确定环境空气中可培养的中温需氧细菌和颗粒物的背景浓度，并分析它们的浓度与一些环境因素之间的关系。在 2019 年 7 月至 10 月期间，使用单级空气采样器和粒子计数器在城市、农村和山区测量了中温需氧细菌和灰尘颗粒的浓度。空气中细菌和灰尘颗粒的浓度以每立方米菌落形成单位（CFU/m）和每立方米颗粒数（pa/m）计数。鉴定出 sp.。山区 30°C 和 37°C 培养的中温需氧细菌的中位数分别为 7.1×10 CFU/m 和 2.3×10 CFU/m，农村地区分别为 1.3×10 CFU/m 和 6.9×10 CFU/m，城市地区分别为 2.1×10 CFU/m 和 6.5×10 CFU/m。高山地区 sp.的中位数为 2.5×10 CFU/m，城市和农村地区为 7.5×10 CFU/m。阳光明媚和刮风天气时细菌浓度较高。在所有三个地区都观察到空气中中温需氧细菌浓度与粗颗粒物浓度之间存在关系。本研究确定 5.0×10 和 4.6×10 CFU/m 之间的值为空气中中温需氧细菌的自然背景浓度，1.2×10 pa/m 和 6.5×10 pa/m 分别为细颗粒物和粗颗粒物的背景浓度。这些结果可作为评估夏季和初秋中温需氧细菌排放源的基线。
