Global Meta-analysis of Airborne Bacterial Communities and Associations with Anthropogenic Activities

Abstract

Airborne microbiome alterations, an emerging global health concern, have been linked to anthropogenic activities in numerous studies. However, these studies have not reached a consensus. To reveal general trends, we conducted a meta-analysis using 3226 air samples from 42 studies, including 29 samples of our own. We found that samples in anthropogenic activity-related categories showed increased microbial diversity, increased relative abundance of pathogens, increased co-occurrence network complexity, and decreased positive edge proportions in the network compared with the natural environment category. Most of the above conclusions were confirmed using the samples we collected in a particular period with restricted anthropogenic activities. Additionally, unlike most previous studies, we used 15 human-production process factors to quantitatively describe anthropogenic activities. We found that microbial richness was positively correlated with fine particulate matter concentration, NH 3 emissions, and agricultural land proportion and negatively correlated with the gross domestic product per capita. Airborne pathogens showed preferences for different factors, indicating potential health implications. SourceTracker analysis showed that the human body surface was a more likely source of airborne pathogens than other environments. Our results advance the understanding of relationships between anthropogenic activities and airborne bacteria and highlight the role of airborne pathogens in public health.

Perspectives on Sampling and New Generation Sequencing Methods for Low-Biomass Bioaerosols in Atmospheric Environments

“…Several studies have compared results obtained by different sampling methods for a given aerosol sample (filter/liquid-based sampler), and bacterial and fungal diversity, and amplicon sequence variants varied greatly between the methodologies 46 , 54 , 56 , 68 . Jiang et al 69 conducted a meta-analysis of 16S rRNA gene amplicon sequencing on 3226 airborne samples, and the results indicated that the significant effect of PCR primer bias on the air bacterial community was higher than environmental variations such as sampling seasons. Furthermore, it has been recognized that NGS is sensitive to environmental DNA contamination during the sample preparation, in particular when treating samples with low microbial biomass 70 .…”

About the Biodiversity of the Air Microbiome

“…Very small quantities of pathogenic bacteria can be transferred with dust particles over very long distances [ 70 ]. The human body surface is a more plausible (compared to other biotopes) source of pathogenic bacteria in the air [ 71 ]. It was revealed that there is a clear dependence between the structure and composition of the bacterial microbiome at an altitude of 10 m above ground level (an island and a peninsula in East Asia) and dust storms in Central Asia [ 69 ].…”

“…A meta-analysis of the results of 42 studies, covering more than 3,000 bioaerosol samples, revealed increased bacterial diversity, and relative abundance of pathogens in the samples associated with anthropogenic activity at collection sites [ 71 ].…”

“…Хотя и в очень низких количествах, но патогенные бактерии могут тоже переноситься с пылевыми частицами на очень большие расстояния [70]. При этом поверхность тела человека является более вероятным (по сравнению с другими биотопами) источником патогенных бактерий в воздухе [71]. Установлена четкая зависимость структуры и состава бактериобиома на высоте 10 м от поверхности суши (остров и полуостров в Восточной Азии) от пылевых бурь в Центральной Азии [69].…”

“…Проведенный метаанализ результатов 42 исследований, в совокупности охватывающих более трех тысяч образцов биоаэрозоля, выявил повышенное разнообразие бактерий и относительное обилие патогенов в образцах, так или иначе ассоциированных с антропогенной активностью в местах сбора [71].…”