Space station astronauts sent horror health warning over ISS conditions

There are many potential dangers of life in space for astronauts including exposure to radiation, the mental health impacts of isolation and confinement, and the effects of weightlessness on the human body.

But scientists have identified a surprising factor which may be causing them to experience immune dysfunction, skin rashes and inflammatory conditions - the International Space Station is too clean.

A study found that the spacecraft’s interior has a much lower diversity of microbes than human-built environments on Earth.

Researchers believe that introducing more microbes from natural sources, such as soil and water, could improve astronauts’ health without compromising hygiene.

Lead author Rodolfo Salido of the University of California, San Diego, said: “Future built environments, including space stations, could benefit from intentionally fostering diverse microbial communities that better mimic the natural microbial exposures experienced on Earth, rather than relying on highly sanitised spaces.”

The research saw astronauts swab 803 different surfaces on the ISS, which was around 100 times more samples than previous surveys have collected.

When the samples were returned to Earth, the bacteria and chemicals present were identified.

Human skin was found to be the main source of microbes throughout the ISS, and chemicals from cleaning products and disinfectants were present throughout the station.

Different modules in the spacecraft had different microbial communities and chemical signatures, with more food-associated microbes in dining and food preparation areas.

The researchers found that the microbial communities found on the ISS were more similar to environments such as hospitals and closed habitats on Earth, and lacked free-living environmental microbes usually found in soil and water.

Writing in the journal Cell, the authors suggested that introducing more microbes from nature could improve human health on the space station.

Previous research has similarly shown that gardening can boost the immune system through exposure to beneficial microbes in soil.

Study co-author Rob Knight, also from UC San Diego, said: “There’s a big difference between exposure to healthy soil from gardening versus stewing in our own filth, which is kind of what happens if we're in a strictly enclosed environment with no ongoing input of those healthy sources of microbes from the outside.”

Mr Salido added: “If we really want life to thrive outside Earth, we can't just take a small branch of the tree of life and launch it into space and hope that it will work out.

“We need to start thinking about what other beneficial companions we should be sending with these astronauts to help them develop ecosystems that will be sustainable and beneficial for all.”