Are there differences in "Relative Risk" comparing winter to summer in non-equatorial cities and no differences in equatorial places?
According to this Dr. Weller's talk , UVA-levels correlate with skin-NO-relase at a population level, and it sounds reasonable. So, equatorial cities should display no change in Relative Risk in the population comparing the winter to the summer, however, non-equatorial cities, like Glasgow, should have higher Relative Risk in the winter than in the summer.
It would be interesting to know the data or plot of "Relative Risk vs. Month of the Year" for different cities with different locations. Or even better, a plot of "Realtive Risk vs UVA levels" to test Dr. Weller's theory.