Anthropogenic impact on airborne bacteria of the Tibetan Plateau
The Tibetan Plateau is a pristine environment with limited human interference, with its aerosol microbiome being primarily influenced by the monsoon and westerly circulations. The diversity and abundance of airborne microorganisms are affected by anthropogenic activities, such as animal farming, agriculture, and tourism, which can lead to increased risks to the ecosystem and human health. However, the impact of anthropogenic activities on airborne microbes on the Tibetan Plateau has been rarely studied. In this work, we investigated the airborne bacteria of areas with weak (glacier) and strong human disturbance (urban), and found that anthropogenic activities increased the diversity of airborne bacteria, and the concentration of potential airborne pathogens. Moreover, airborne bacteria in glacial aerosols demonstrated significant differences in their community structure during Monsoon- and Westerly-affected seasons, while this pattern was weakened in urban aerosols. Additionally, urban aerosols enriched Macrococcus and Microbacterium, which are potential pathogens from anthropogenic sources, whereas glacier aerosols enriched Acinetobacter and Enterococcus, which are thought to be sourced from surrounding grasslands. This study evaluated the impact of human activities on airborne bacteria in the Tibetan Plateau and establishes a foundation for predicting the impacts of climate change on plateau atmospheric microbes