Astronauts are at risk for decreased bone strength
Astronauts living on the International Space Station loose significant bone strength increasing the risk for fractures later in life.
Research has evaluated 12 astronauts who spent 4 – 6 months on the International Space Station and found that on average their hip bone strength decreased 14%.
Three astronauts experienced losses of 20 – 30%, a rate comparable to that seen in very old women with osteoporosis.
This is indeed a very serious problem for space travelers. I’m not sure how NASA is going to address this, but it has to be solved because these astronauts are being put at tremendous risk once they return to land from their space station experience.
It appears that people will be subject to some very major public health issues if they spend a prolonged period of time in space.
Plans to send humans to other planets such as Mars, which could take years to travel there and return would be subjecting these travelers to unbelievable risks.