A MATHEMATICAL ANALYSIS ON THE INCIDENCE OF RAYNAUD'S PHENOMENON IN CHAIN SAW OPERATORS

By inquiring of sufferers from Raynaud's phenomenon in chain saw operators as to the period from the beginning of chain saw use to the first appearance of that phenomenon, we found that accumulated number of sufferers n at the time tincreases with time according to the equation: n=a log t+b, where, n is accumulated number of sufferers from Raynand's phenomenon at the time t, t is elapsed time from the beginning of chain saw use to the first appearance of Raynaud's phenomenon (in years), and a and b are constants. On the hypothesis that the sufferer's group consists of two sub-groups, which are supposed to exist by mathematical analysis but not yet identified, we set up two logarithmic equations for them respectively. Sum of n of both sub-groups at the time t fits farely well the observed number.