Flu epidemics coincide with solar eruptions, B.C. study says
You're coughing, you're sneezing, you think you've just got the flu, but you could be a victim of sunspots
VANCOUVER - Influenza epidemics are more likely to sweep the globe when the sun develops spots and sends its excess energy barrelling toward Earth, according to Canadian researchers.
"Epidemics are four times as likely during solar maxima," says Ken Tapping, a solar physicist with the National Research Council, pointing to the striking correlation between flu pandemics and the peaks of the 11-year sunspot cycle, also known as the solar maximum.
He and two colleagues have compared flu and solar records dating back to 1729 and found a statistically significant connection. There were flu epidemics, some of them killing millions of people, in 1729, 1830, 1918, 1957, 1968 and 1977, years when solar activity and flares bombarded the Earth with extra radiation and cosmic rays.
There were also close correlations in other years, but they were not as pronounced. The probability of the matches happening by chance is less than 2%, the researchers say in a report to appear in the Canadian Journal of Infectious Diseases.