[Medical prevention of chronic occupational intoxications due to metallic mercury]

A group of workers exposed to elemental mercury was monitored over a period of 14 years (1983-1996) at the Institute of Occupational Medicine and Environmental Health, Sosnowiec. Mercury was used as a catalyst in the synthesis of acetic aldehyde and obtaining of chlorine. Every year medical examination was performed in the group of 163-277 persons. During the first four years of monitoring, excessive absorption of Hg was found in 32.1-45.1% of workers. The highest percentage (46.1-65.0%) was observed in persons engaged in technological processes of acetic aldehyde synthesis. From 1987 workers employed in this department were systematically (every six months) removed from the contact with Hg. Due to preventive removal a gradual decrease in the percentage of those with high Hg absorption (32.0-9.2%) was observed. As the authors point out, it is important to select properly workers to be employed under conditions of mercury exposure, and to determine every six months their urine mercury level. It is also desirable to remove workers temporarily from the most hazardous workposts and to incorporate a wide spectrum of specialistic examinations into periodical checkups.