An epidemiologic study of the relation between symptoms of fatigue, dental amalgam and other factors.

Fatigue has been described as a symptom of mercury toxicity. The aim of this pilot study was to investigate whether fatigue is related to the number of tooth surfaces of amalgam or to other factors. The study population was a group of 108 hospital workers who completed a self administered questionnaire including questions about fatigue in a study (1983) to determine the effects of exposure to glutaraldehyde. The 39 women who gave positive answers to one or two of the questions about fatigue were assigned cases. The referents were chosen with regard to sex, age and smoking habits among those who gave negative answers to both questions. Information about the number of surfaces of amalgam was received from dentists. Analysis showed that the cases and referents were not significantly different in terms of the mean number of surfaces of amalgam. There was a significant positive relation between the number of surfaces of amalgam and age as well as smoking habits. A significant positive relation was also found between symptoms of fatigue and psychosocial factors and the frequency of sick-leave in respiratory diseases. In conclusion other factors rather than the release of mercury from dental amalgam could explain the symptoms of fatigue.