Health Risks for Astronauts
If you’ve checked the news today, you must have heard that NASA is facing more delays in the launch of the James Webb telescope. While this is an unmanned spacecraft, it does make you wonder about the health challenges faced by an astronaut. Some of these are as follows:
- Loss of cardiac muscle mass
A studyconducted in 2014 found that since gravity is weaker in outer space, the human heart doesn’t work as hard as it needs to while an astronaut is on Earth. This results in a slight loss of muscle mass, which can potentially cause serious complications once the astronaut is back on terra firma.
- Temporary / permanent hearing loss
It has been found that even a single shuttle mission can result in a temporary or permanent loss of hearing in varying degrees. Most often, it is the ability to perceive higher frequencies, that is affected. This has been attributed to a number of factors from simple (the sheer amount of noise within a space shuttle) to slightly more complex (cabin pressure, atmospheric contaminants, inter-cranial pressure).
- Kidney stones
Astronauts are seemingly at a much higher risk for developing kidney stones, because bones begin to dematerialize when in a weightless environment for an extended period of time. This encourages release of salts like calcium phosphate into the bloodstream. These salts end up concentrating in the kidneys, forming stones that range from microscopic to walnut-sized.The risk is further compounded by the fact that astronauts are also exposed to microgravity, which makes blood volume decline.
- Changes in immune system
It’s common knowledge that your immune system is adversely affected by factors such as sleep deprivation, poor nutrition and stress. However, these factors are magnified for astronauts on an extended space mission, thus turning even a simple cold into a serious threat to their health. The fundamental distribution of immune cells doesn’t really change, but their responsiveness does begin to fluctuate significantly, leading to a “confused” immune system. When the immune system underreacts, your body is open to attack from dormant viruses. When it overreacts, you break out in allergies and/ or rashes.
- Vision Loss
Studies conducted in the US on roughly 300 astronauts since 1989 have found that the longer the time spent in outer space, the more likely the astronauts were to develop eyesight problems.Testing revealed that in some cases, the backs of both eyeball had become flattened, leading to more farsightedness. Scientists have attributed this to the rise of a person’s bodily fluids when in a weightless environment. In this particular case, pressure seemed to have built up from inside the person’s skull due to increased flow of cerebrospinal fluid to their head. The fluid cannot expand bone, so it went on to flatten the back of the eyeball instead.