ECOLOGICAL CORRELATES OF MOTOR-NEURON DISEASE MORTALITY - A HYPOTHESIS CONCERNING AN EPIDEMIOLOGIC ASSOCIATION WITH RADON GAS AND GAMMA-EXPOSURE

This study investigates variations in motor neuron disease (MND) morta lity rates between the counties of England and Wales from 1981 to 1989 , and their relationship with gamma-ray dose rates, indoor radon gas c oncentrations and enhanced general life expectancy. A stong correlatio n was confirmed between age-adjusted rates of MND mortality and life e xpectancy. Weaker, but statistically significant, associations were ob served between indoor radon gas concentrations, terrestrial gamma radi ation and marginal variations in MND mortality. Life expectancy and ra don gas concentrations were positively associated with MND mortality r ates whilst gamma radiation was negatively associated. The negative co rrelation of gamma radiation with MND mortality may be understood with reference to its negative effects on overall population life expectan cy. Radon gas concentrations seemingly account for a small elevation i n MND mortality, amounting to at most 4% of total deaths. Further rese arch is required to investigate this association.