Yes, it does. It destroys the knees of the astronaut after long time. They have the risk of looking older as they grow.
no
contamination of groundwater
Most workers risks their lives for their job. Factory and refinery workers die at a much higher rate than astronauts. More astronauts have died in plane crashes and car accidents than have died in space. While being an astronaut seems more dangerous than most jobs, there are countless safety factors built into the spacecraft and the flight plan that don't exist in most other earthly workplaces. There's obviously a risk to space travel, but NASA and the astronauts make sure their vehicle is as safe as possible to minimize those risks as much as is humanly possible.
cough
yes
yes
Hiv
they do bubble up their drinking water in the weightlessness of space, within the shuttle, but they keep close watch that it wont go elsewhere that would render risk to their machine. They do exercise on their treadmill
Yes
Vitamins A and D
a lack or gravity
The practice known as universal precautions makes the assumption that those bodily fluids pose a risk for transmission of HIV.