Characterizing atmospheric biological aerosols at a suburban site in Guangzhou, southern China by airborne microbes, proteins and saccharides

• Published in: The Science of the total environment 2023-07, Vol.883, p.163543-163543, Article 163543
• Main Authors: Lin, Xiaoluan, Pei, Chenglei, Liu, Ting, Shu, Qiuzi, Hong, Dachi, Huang, Zhuoer, Zhang, Yingyi, Lai, Senchao
• Format: Article
• Language: English
• Subjects: Aerosols - analysis; Air Microbiology; Air Pollutants - analysis; air pollution; Air Pollution - analysis; Airborne microbes; Atmospheric environmental impact factors; bioaerosols; Carbohydrates; China; environment; Environmental Monitoring - methods; oxidation; Particulate Matter - analysis; pollen; Proteins; Saccharides; Seasons; soil; spring; winter
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.163543

Bioaerosols in ambient environment can be evaluated using various techniques. However, the results of bioaerosols obtained using different methods are rarely compared. The relationships between different bioaerosol indicators and their behaviors under the influence of environment factors are seldom investigated. Here we used airborne microbial numbers, proteins and saccharides concentrations as the indicators to characterize bioaerosols in two seasons with different source contribution, air pollution situation and meteorological conditions. The observation was conducted at a suburban site in Guangzhou, southern China, during the winter and spring periods of 2021. Airborne microbes were observed with an average of (1.82 ± 1.33) × 106 cells/m3, converted to the mass concentration level of 0.42 ± 0.30 μg/m3, comparable but lower than that of proteins (0.81 ± 0.48 μg/m3). Both of them were much higher than the average concentration of saccharides (19.93 ± 11.53 ng/m3). During the winter period, significant and good correlations were observed between the three components. In spring, a biological outbreak was observed in late March with a strong elevation of airborne microbes followed by elevations of proteins and saccharides. The retardation of proteins and saccharides could be the result of the enhanced release from microorganisms under the influence of atmospheric oxidation processes. Saccharides in PM2.5 were studied to reveal the contribution of specific sources of bioaerosols (e.g. fungi, pollen, plants and soil). Our results show that primary emissions and secondary processes should play their roles in the variations of these biological components. By comparing the results of the three methods, this study provides an insight into the applicability and variability of bioaerosol characterization in the ambient environment with respect to various influences of sources, atmospheric processes and environmental conditions. [Display omitted] •Airborne microbes, proteins and saccharides are useful indicators of airborne bioaerosols.•Significant differences were observed between airborne microbes, proteins, and saccharides during a biological outbreak.•Atmospheric oxidation processes affect the release of proteins from airborne microbes.