Study Indicates CO2 May Cause Astronauts' Headaches
The research reported in the Journal of Occupational and Environmental Medicine found increased incidence of them during periods of higher CO2 levels on the International Space Station.
The cause of headaches suffered by astronauts aboard the International Space Station appears to be elevated levels of carbon dioxide (CO2), researchers report in a study published in the May Journal of Occupational and Environmental Medicine. It's the official publication of the American College of Occupational and Environmental Medicine. Dr. Jennifer Law, flight surgeon at the NASA Johnson Space Center, headed the team that analyzed data on CO2 levels and headaches reported by ISS crew members between 2001 and 2012. They found headaches were more frequent when CO2 levels were higher.
For each 1 mm Hg (millimeter of mercury) increase in CO2 the odds of a headache reported by crew members doubled. Headaches were less frequent in older crew members and those with more days in flight, they concluded.
Their paper said higher CO2 levels also apparently are related to other symptoms, such as sleep problems, fatigue, and irritability. After steps were taken to keep CO2 levels on the station at 4 mm Hg or less, the risk of headache decreased from about 3.3 to 1.6 percent per week.
The article's citation is Law J, Van Baalen M, Foy M, et al., "Relationship between carbon dioxide levels and reported headaches on the International Space Station." J Occup Environ Med. 2014; 56(5):477-83.