Space mold is a worry

If you think that going to live in space might be a cure for mundane Earthly problems like too much mold around your apartment - think again.

Science magazine explains that mold is a persistent problem in the International Space Station - they even have a photo of a patch:

[I would presume that one of the big problems is that bleach fumes are not something you want to have to deal with in a recycling air system.]

What's worse - mold spores can tolerate incredible amounts of radiation:

Astronauts on the International Space Station (ISS) already constantly battle with mold, which grows on the station’s walls and equipment. That mold, of course, is in a protected structure in low-Earth orbit, where radiation doses are low. Outside of the station, doses are higher—and they would be higher still on the hull of a spacecraft going to Mars or beyond.

To find out what might happen to mold there, Marta Cortesão, a microbiologist at the German Aerospace Center (DLR) in Cologne and colleagues beamed x-rays and heavy ions at a common black mold called Aspergillus niger, which is plentiful in the ISS. The researchers fired “stupid amounts” of radiation, Cortesão says—much more than encountered on a Mars-bound spaceship (0.6 gray per year) or on the surface of Mars (0.2 gray per year). The gray is a measure of the amount of absorbed radiation energy.

The researchers discovered that the spores could survive radiation doses of 500 to 1000 gray, depending on which type of radiation they were exposed to. Humans, by contrast, get radiation sickness at doses of 0.5 gray and are killed by 5 gray. Cortesão also found that the spores survived large amounts of high-energy ultraviolet radiation, which is commonly used as a hospital disinfectant and has been proposed for sterilizing the surfaces of spacecraft.

Cortesão cautions that her research focused only on radiation and did not include all aspects of the harsh outer space environment. But, she says, at least one older study suggests that mold spores resist radiation even better in a vacuum. Meanwhile, one thing is certain, she says: “We will have spores with us for sure in our space travels. Fungi have been forgotten for the past 20 or 30 years, but it’s time to go back to them.”