These can be compared to normal values of 0.8 μg/100 ml in blood (Study Group on Mercury Hazards, 1971) and 8 μg/L in urine (Solloman, 1957).

Lauwerys and Buchet (1973) reported on 40 chemical and biologic workers chronically exposed to mercury vapors and 23 biologic technicians who had not been exposed (controls). The data are summarized below.

Increased plasma galactosidase and plasma catalase activities were also detected.

Factory workers exposed to elemental mercury (in a mercury cell chlorine plant) were found to have ulnar nerve conduction deficits when their urinary excretion of mercury exceeded 250 μg/L, despite the fact that they were asymptomatic and appeared normal when examined by an industrial physician (Levine et al. 1982).

Other mercury studies are reported in Threshold Limit Values (ACGIH, 1980). There is no evidence that exposure to mercury leads to excess cancer mortality in humans (Woo and Arcos, 1981).

Acute Toxicity

Rabbits exposed for 4 h to saturated vapors of mercury (27 mg/m³) suffered severe poisoning of brain, colon, heart, liver, lungs, and kidneys (Ashe et al. 1953).

The rat oral LD₅₀ of HgCl₂ is 210 mg/kg.

Subacute Toxicity

Guinea pigs exposed 10 h/d for 4 d to mercury vapor at 6 mg/m³ developed neurotic effects and hemorrhagic colitis. Mercury was stored in the kidneys (Holzmann, 1931).

Chronic Toxicity

Dogs, rabbits, and rats showed no effects when exposed to mercury vapor at 0.1 mg/m³ for 83 wk (Fraser et al., 1934)