Recent research sampling the upper troposphere has uncovered a diverse array of microbial species, including some human pathogens, raising concerns about the global transport of potentially harmful organisms. While many of the microbes were found to be dead, having succumbed to the cold temperatures, increased radiation, and lack of nutrients, others proved surprisingly resilient. These hardy microorganisms, capable of surviving harsh conditions, may travel great distances through high-altitude winds.
Researchers find live fungi, bacteria and viruses high in the Earth’s atmosphere: https://t.co/VEFzBQK7xB
— Ken Gusler (@kgusler) September 10, 2024
The study draws on Carl Sagan’s speculative dreams of life existing in the clouds of distant planets like Jupiter and Venus. While those ideas have largely fallen out of favor, researchers are still investigating whether life can thrive at high altitudes on Earth. In this study, a Spanish-Japanese research collaboration sampled life from the upper troposphere, particularly focusing on the region over Japan.
The troposphere, the lowest level of Earth’s atmosphere, stretches from ground level to approximately 18 kilometers (11 miles) above sea level. Within this layer, the planetary boundary zone—also known as the peplosphere—represents the area closest to the surface, where air behavior is influenced by factors such as heat and turbulence. It is already well-known that life thrives in the peplosphere, but this study aimed to explore whether microbial life extends beyond that layer.
Sampling took place during ten flights at altitudes above the peplosphere, revealing a surprisingly diverse biological environment. The team collected more than 266 genera of fungi and 305 genera of bacteria. While many of these organisms were not uniquely adapted to extreme conditions like Deinococcus radiodurans, several were identified as potential pathogens.
Of particular concern were familiar pathogenic species like E. coli and Staphylococcus, both of which were found to be viable in culture after enduring the extreme conditions of the upper atmosphere. This raises questions about whether harmful bacteria could travel across the globe via high-altitude winds, potentially spreading disease.
Past research has shown that organisms can attach to dust particles and travel long distances, such as from Africa to the Caribbean, where they have been known to harm coral reefs. However, this new study demonstrates that similar long-range transport of pathogens is not an isolated incident. In this case, the organisms sampled are believed to have originated from an agricultural region in northeastern China, more than 2,000 kilometers (1,243 miles) from the sampling site in Japan. This represents one of the longest reported transport distances of harmful species.
In 10 flights over Japan, researchers found a host of bacteria and fungi. These high-altitude germs could help spread disease around the world. https://t.co/IxS6GzOZcz
— NYT Science (@NYTScience) September 10, 2024
While the researchers are cautious not to draw direct links between the presence of these pathogens and specific health effects, the study suggests that poor sewage disposal practices could contribute to the spread of disease far from the original source.
One intriguing finding from the research was the seasonal variation in the abundance of certain species. For example, microbial species typically found in the human mouth and intestines were more abundant in April compared to February, though further research is needed to confirm an annual pattern. Additionally, fungi that can opportunistically infect humans were found to be widespread in both months.
Key Points:
i. A study sampling the upper troposphere over Japan found a diverse array of microbial species, including over 266 genera of fungi and 305 genera of bacteria.
ii. Some of the microbes were human pathogens, such as E. coli and Staphylococcus, raising concerns about the long-distance transport of potentially harmful organisms.
iii. The study revealed that some pathogens survived extreme conditions, suggesting they could be transported globally by high-altitude winds.
iv. Microorganisms from northeastern China were found 2,000 kilometers away in Japan, marking one of the longest reported pathogen transport distances.
v. Seasonal variations in microbial species were observed, with human-associated microbes more prevalent in April than February, though more research is needed to confirm these patterns.
Al Santana – Reprinted with permission of Whatfinger News
