O. Iwami et al., MOTOR-NEURON DISEASE ON THE KII PENINSULA OF JAPAN - EXCESS MANGANESEINTAKE FROM FOOD COUPLED WITH LOW MAGNESIUM IN DRINKING-WATER AS A RISK FACTOR, Science of the total environment, 149(1-2), 1994, pp. 121-135
To identify important risk factors of motor neuron disease (MND) in a
focus (Hohara) on the Kii peninsula of Japan, 24-h dietary duplicates,
rice, drinking water, and soils were analysed for metals in Hohara an
d control areas. The manganese content in 24-h food in Hohara was sign
ificantly (P < 0.01) higher than that in the remote control areas. The
incidence of MND in Hohara was well explained by the two parameters,
manganese content in food and the magnesium concentration in drinking
water (r2 = 0.99), suggesting that MND in this focus can be understood
as a result of excess intake of manganese from food coupled with low
intake of magnesium from drinking water. The reference to epidemiology
and occupational medicine supports this conclusion. The crude annual
MND incidence per 10(5) population in other foci may be predicted as M
ND=e(alpha) ln[beta(Mn in food)gamma/(Mg in water)], where alpha is 5.
389-5.748, beta is 0.170-0.166, and gamma is 1.239-1.226.