Understanding the air composition and presence of bacteria aboard the International Space Station (ISS) is important to preserve the health of its astronauts and to keep its instrumentation in working order. A new study has performed a cleanliness check of the Space Station and found the presence of pathogens, which are mostly harmless on Earth, that could possibly lead to infections in space.
When it comes to living in space, we still have a lot to learn. Gaining insight of life aboard the ISS is not only important for the astronauts working there, but also for planning future long-term missions to the Moon and to Mars. There’s nothing quite like the ISS; it’s a microgravity environment with elevated carbon dioxide levels, continuous human occupation and under a constant bombardment of cosmic rays.
The researchers wanted to figure out the microbiome – the composition and number of microbes – of the ISS. To do so, the team gathered air filter samples and vacuum bag dust from the station and compared them to the dust from NASA’s clean rooms, which are rooms under strict environmental control that are used for scientific research or manufacturing and are easily affected by airborne factors. Clean rooms are a close match to the ISS, but some fundamental differences exist: clean rooms circulate fresh air, they are not occupied around the clock, and they can be used by a large number of people.
The study used DNA sequencing in order to quickly and accurately look for the presence of potentially pathogenic organisms. As described in Microbiome, they found more than 75 species of bacteria, including a mold that releases an acid that corrodes metal, glass, and rubber. Of those, they found that the largest bacterial population belonged to the group Actinobacteria, which are commonly associated with human skin. The study also highlighted that two opportunistic pathogens – those that can cause problems if the host's defenses are compromised – are present in the ISS.
"By using both traditional and state-of-the-art molecular analysis techniques we can build a clearer picture of the International Space Station's microbial community, helping to spot bacterial agents that may damage equipment or threaten astronaut health, and identify areas in need of more stringent cleaning," lead author of the study, Kasthuri Venkateswaran, said in a statement.
While the study expanded our understanding of the potential microbiological hazards within the ISS's environment, it did not assess the virulence of the bacteria found, meaning their ability to invade and cause infections or disease. So at this stage, it's difficult to draw conclusions on the health risks these organisms may pose to the astronauts, but hopefully further work will shed light on this area.