In order to obtain a comprehensive picture of the dental staff (11 dental office in Tokyo area) whom how mercury from amalgam has influenced, the authors preformed a number of experiments which could be summarized as follows:
1. Analyses of the urine of dentists, dental hygienists, dental nurses and dental technicians completed the picture of the mercury exposure of the dental staff. The colorimetric procedure of choice was carried by the dithizone method (a simplified method for determing mercury in urine) by Nishimura and Aoki.
The mercury concentration in urine in 40 dental staff persons was 109.8μg/l in average, ranging from 6 to 588μg/l.
2. High concentration of mercury was excreted in urine of those who had frequent chance of doing amalgam treatment (a dental hygienists and a nurse, each one case). The mercury concentration was each 332μg/l and 588μg/l.
3. No relation was found between the dental career and urinary mercury concentration.
4. A relation was observed between the frequency of doing amalgam treatment and the urinery mercury concentration, which was varied by good or poor air conditioning of dental offices.
5. The air mercury concentration of the dental office in buildings was influenced by temperture and ventilation.
The air concentration of mercury in the air conditioned office was 0.09mg/m3, the air of which was collected one meter apart from amalgam procedure spot.
In case of two offices without air conditioning, the mercury concentration was each 0.15mg/m3 and 0.2mg/m3.
6. Urinery mercury concentration of 5 persons whose amalgam procedure was mainly performed by means of hands, was 520, 250, 240, 70 and 180μg/l respectively.
