Astronauts on the seven-month journey to Mars are at increased risk of deafness and balance problems, according to a new study.
Researchers at the Medical University of South Carolina used MRS scans to find that long space missions can cause fluid buildup in the ear.
An accumulation of fluid in the ear can cause hearing loss and dizziness – a condition called ‘mastoid effusions’ – that affect the bone at the back of the ear.
Donald Trump wants the first manned mission to Mars to take place in 2033. The journey takes approximately seven months – longer than astronauts currently remain on the ISS.
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Astronauts on board the International Space Station spend an average of six months in space. The new study found that this puts them at greater risk for an ear condition that can cause deafness. This is a photo of Christina Koch in space – but is not linked to this study
The study included MRI scans of 35 astronauts – 17 from the NASA Space Shuttle program team, and 18 of them spent time on the International Space Station.
Traveling outside of Earth’s atmosphere to the far regions has long been compared to doing a headstand – due to gravity, researchers say.
A study found that on six-month (ISS) expeditions, astronauts were more than nine times more likely to have a condition called “ mastoid effusions. ”
This was compared to those who participated in shorter Space Shuttle missions of about two weeks.
The mastoid bone is located at the back of the ear and contains air cells that are essential to hearing – when fluid collects in this area, it can cause pain and decreased ability.
Corresponding author Dr. Donna Roberts of the Medical University of South Carolina said there was a direct link between ISS conditions and mastoid effusions.
Head congestion is one of the most common symptoms astronauts experience when their nose, ears and eyes become clogged with fluid.
Space flights cause more than three and a half liters of blood to shift upwards, from the lower body to the upper body.
The study published in JAMA Otolaryngology – Head & Neck Surgery is the first to measure the effect on the sinus mastoid air cells.
The study found no differences in the astronauts’ sinuses.
Long-term spaceflight, however, was associated with a 9.28 greater risk of mastoid effusions compared to short-term.
This may be because it damages tubes and blood vessels that connect the inner ear to the back of the throat and head, Dr. Roberts explained.
She said without gravity, astronauts experience nasal congestion and head pressure, but there is little data on physiological changes of the paranasal sinuses or mastoid air cells.
NASA has avoided using CT (computed tomography) scans to limit the dose of radiation astronauts receive, given the exposure they experience during spaceflight.
But as part of the routine medical protocol, they all undergo pre- and post-flight MRI scans of the head.
Her team took advantage of reviewing these scans – all of which were obtained before and after Space Shuttle or ISS missions.
“Prolonged space flight on the ISS is associated with an increased incidence of mastoid effusions,” said Roberts.
The cause of this phenomenon is likely to be multifactorial, but possible explanations may reflect various conditions associated with effusions seen on Earth.
“Further research is needed to provide a definitive explanation for the development of these effusions and to determine whether these results can be applied to more than this small astronaut population.”
The study compared scans of astronauts during the two-week space shuttle missions to those of astronauts from the International Space Station who spend approximately six months in space
Astronauts on the International Space Station who spend more than six months in space have a 9 times greater risk of contracting an inner ear condition that can lead to deafness
Dr. Michael Stenger, of NASA’s Human Research program, who was not involved in the study, said the implications should be better understood by space doctors.
New medical requirements will be needed for upcoming off-Earth exploration missions, Stenger Siad.
This is because a mastoid effusion can increase the risk of debilitating earache.
“On the ISS, in case of a medical emergency, astronauts can orbit and be treated relatively quickly, within hours.
“During a mission to the Moon or Mars, treatment would be limited to the supplies and techniques available on the vehicle.”
Possible solutions include simulating Earth such as gravity on the Mars spaceship or thigh cuffs that can collect blood in the legs.
“The space research and the medical community are working aggressively to identify the correct magnitude and duration of these countermeasures,” said Stenger.
“This work is becoming more and more important as more new consequences of long-term space flights are discovered.”
He said it was an exciting time in human spaceflight with the arrival of commercial operators and the upcoming manned missions to the moon.
“Although it’s been 50 years since the Apollo 11 moon landing, and 20 years since humans continuously lived on the ISS, researchers continue to make new discoveries related to the human body in space,” Stenger said.
The findings are published in the journal JAMA Otolaryngology – Head and Neck Surgery.
HOW DOES SPACE RADIATION AFFECT THE HEALTH OF ASTRONAUTS?
Astronauts traveling to Mars are likely to be bombarded with 700 times the radiation experienced on Earth.
Even on the International Space Station, astronauts are exposed to 200 times more radiation as a result of their work than a pilot or radiology nurse would experience.
As a result, NASA constantly monitors weather information in local space.
If a burst of space radiation is detected, mission control in Houston, Texas, can instruct astronauts to abort spacewalks, move to more shielded areas of the orbit laboratory, and even adjust the height of the station to minimize any health impact.
Solar flare activity can cause acute effects of radiation exposure – such as changes in the blood, diarrhea, nausea, and vomiting – that can be restored and other effects that are irreversible and / or fatal.
Long-term bombardment with cosmic rays is a bigger concern.
This can increase the risk of cancer, cause cataracts and cause sterility.
It can also cause damage to the brain, central nervous system and heart, paving the way for various degenerative diseases.
DNA changes due to space radiation can even be passed on to subsequent children.