In a groundbreaking study, researchers have unveiled that microorganisms can traverse vast distances in the troposphere, potentially impacting human health. Conducted by a team from the Barcelona Institute for Global Health (ISGlobal) and published in the Proceedings of the National Academy of Sciences, this research highlights the resilience of microbes in high-altitude environments.
On September 9, 2024, a Cessna aircraft was employed to collect samples at altitudes between 1,000 and 3,000 meters above Japan, specifically near Tokyo. The team, led by ICREA researcher Xavier Rodó, meticulously planned flights to follow wind currents originating from continental Asia, creating what are known as tropospheric bridges. These currents can transport air and its microbial inhabitants over thousands of kilometers.
During two sampling periods in February and April 2014, the scientists analyzed 22 aerosol filter samples, revealing a staggering diversity of over 266 genera of fungi and 305 genera of bacteria. Among the identified species were notorious pathogens such as Escherichia coli and Clostridium difficile, which can pose significant health risks to vulnerable populations.
Rodó emphasized the importance of these findings, stating, "Our study reveals for the first time a vast diversity of microbes that propagate through wind currents thousands of kilometers from their origin." This discovery marks a paradigm shift in understanding how airborne pathogens can affect human health.
While the study does not establish a direct link between airborne pathogens and health effects, it underscores the urgent need for further exploration into how these microbes travel and their potential implications. Notably, the researchers found that some bacteria collected from the air were not only viable but also exhibited resistance to commonly used antibiotics, raising concerns about the spread of antimicrobial resistance.
Co-author Sofya Podzniakova remarked, "Our findings suggest that antimicrobial resistance could spread over great distances through this previously unknown pathway." This research not only expands our understanding of microbial ecology but also poses new questions about public health and the measures needed to mitigate potential risks.