ABSTRACT
Urinary excretion of mercury was determined in 32 workers of Chemical plant of No. (1) Pulp and Paper Mill in Sittaung. For comparison, it was also measured in 10 Clerical Staff (nonexposed) of the said factory and 10 Technician Grade I students of Health Department. Signs and symptoms of chronic metallic mercury poisoning were looked for in all subjects. The air concentration of mercury vapour at different times of the working hours in the Chlorine PLant was measured. The mean + or - SD urinary mercury excretion was significantly higher in exposed workers 59.22+ or -22.44 ugm/L than non exposed workers of the factory (29.3+ or -8.64) (p <0.001). Comparison of the mean + or - SD urinary mercury levels of the nonexposed workers of the factory and technician students (19.4+ or -8.59) indicated that the former had significantly higher mercury excretion (p < 0.001). There was an increasing trend of mercury excretion with increased duration of exposure (r = 0.54; p <0.05). Signs and symptoms of chronic mercury poisoning were not found in any subject. The concentration of mercury vapour in Chlorine Plant during the working hours was found to 0.1 to 0.25 mgm/m of air (2 to 5 times TLV).