Numerous studies have focused on occupational and indoor environments because people spend more than 90% of their time in them. Nevertheless, air is the main source of bacteria in indoors, and outdoor exposure is also crucial. Worldwide studies have indicated that bacterial concentrations vary among different types of outdoor environments, with considerable seasonal variations as well. Conducting comprehensive monitoring of atmospheric aerosol concentrations is very important not only for environmental management but also for the assessment of the health impacts of air pollution. To our knowledge, this is the first study to present outdoor and seasonal changes of bioaerosol data regarding an urban area of Poland. This study aimed to characterize culturable bacteria populations present in outdoor air in Gliwice, Upper Silesia Region, Poland, over the course of four seasons (spring, summer, autumn and winter) through quantification and identification procedures. In this study, the samples of bioaerosol were collected using a six-stage Andersen cascade impactor (with aerodynamic cut-off diameters of 7.0, 4.7, 3.3, 2.1, 1.1 and 0.65 μm). Results showed that the concentration of airborne bacteria ranged from 4 CFU m−3, measured on one winter day, to a maximum equal to 669 CFU m−3 on a spring day. The average size of culturable bacterial aerosol over the study period was 199 CFU m−3. The maximal seasonally averaged concentration was found in the spring season and reached 306 CFU m−3, and the minimal seasonally averaged concentration was found in the winter 49 CFU m−3. The most prevalent bacteria found outdoors were gram-positive rods that form endospores. Statistically, the most important meteorological factors related to the viability of airborne bacteria were temperature and UV radiation. These results may contribute to the promotion and implementation of preventative public health programmes and the formulation of recommendations aimed at providing healthier outdoor environments.

中文翻译：

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气象因素对格利维采空气中可培养细菌水平和特征的影响，上西里西亚（波兰）

许多研究都集中在职业和室内环境上，因为人们 90% 以上的时间都在这些环境中度过。然而，空气是室内细菌的主要来源，户外暴露也至关重要。世界范围内的研究表明，细菌浓度在不同类型的户外环境中有所不同，季节性变化也很大。对大气气溶胶浓度进行综合监测不仅对环境管理非常重要，而且对评估空气污染对健康的影响也非常重要。据我们所知，这是第一项展示波兰城市地区生物气溶胶数据的室外和季节性变化的研究。本研究旨在表征波兰上西里西亚地区格利维采室外空气中存在的可培养细菌种群，在四个季节（春、夏、秋、冬）的过程中，通过量化和识别程序。在这项研究中，生物气溶胶样品是使用六级 Andersen 级联撞击器（空气动力学截止直径为 7.0、4.7、3.3、2.1、1.1 和 0.65 μm）收集的。结果表明，空气中细菌的浓度范围从一个冬日测量的 4 CFU m-3 到春天一天的最大值 669 CFU m-3。研究期间可培养细菌气溶胶的平均大小为 199 CFU m-3。最大季节性平均浓度出现在春季，达到 306 CFU m-3，最小季节性平均浓度出现在冬季 49 CFU m-3。在户外发现的最普遍的细菌是形成内生孢子的革兰氏阳性杆菌。据统计，与空气中细菌的生存能力有关的最重要的气象因素是温度和紫外线辐射。这些结果可能有助于预防性公共卫生计划的推广和实施，以及旨在提供更健康的户外环境的建议的制定。