Comparison of renal function and psychomotor performance in workers exposed to elemental mercury

Abstract

Renal function and psychomotor performance (eye-hand coordination, arm-hand steadiness) of a group of 43 workers exposed to mercury vapor were examined. Their mean age an average duration of exposure to mercury were 38 and 5 years, respectively. The results were compared with those in a matched group of 47 control workers. Increased proteinuria and albuminuria were found slightly more prevalent in the Hg-exposed group than in the control workers. These results are in agreement with those found during a previous study carrier out in another group of workers also exposed to elemental mercury (Buchet et al. 1980). The scores of the psychomotor tests were less satisfactory in the Hg workers than in the control workers, the arm-hand steadiness test being more discriminative than the eye-hand coordination test. Preclinical changes in psychomotor function can be detected independently of the presence of signs of renal dysfunction. No clear-cut relationships were found between the prevalence of abnormal psychomotor scores and the level of mercury in blood (HgB) or in urine (HgU). Increased prevalences of abnormal psychomotor scores seem however to occur for HgB between 1 and 2 micrograms/100 and for HgU between 50 and 100 micrograms/g creatinine. Therefore, a biologic threshold limit value of 50 micrograms/g creatinine in proposed for urinary mercury to prevent the development of preclinical effects on the central nervous system. A similar critical HgU level based on renal dysfunction prevalences has been suggested in a previous study.

Renal and immunologic markers for chloralkali workers with low exposure to mercury vapor

“…The longterm consequences are not well known, but one epidemiologic study on formerly exposed chloralkali workers suggests that an increased U-NAG level may be reversible (38). Our study did not reveal an increased concentration of U-Alb, and this result is in accordance with the findings of several other epidemiologic studies (3)(4)(5)(6)(7)(9)(10)(11).…”

“…Although an increased urinary excretion of albumin (UAlb), indicative of glomerular basement membrane affection, has been reported (8), most epidemiologic studies are nonpositive (3)(4)(5)(6)(7)(9)(10)(11). An increased prevalence of autoantibodies to the glomerular basement membrane (anti-GBM) has been reported for animals (mainly the Brown-Norway rat).…”

Mercury derived from dental amalgams and neuropsychologic function.

“…Unlike our study, where exposure levels were very low, occupational studies of workers in the thermometer and chloralkali industries find associations between UHg level and both neurologic and neuropsychologic deficits (Albers et al 1988;Ehrenberg et al 1991;Fawer et al 1983;Herber et al 1988;Langolf et al 1978Langolf et al , 1981Miller et al 1975;Piikivi and Hanninen 1989;Ritchie et al 1995;Roels et al 1982;Smith and Langolf 1981;Smith et al 1970Smith et al , 1983. Neurologic deficits include increased intention and resting tremor (Albers et al 1988;Ehrenberg et al 1991;Fawer et al 1983;Langolf et al 1978Langolf et al , 1981Roels et al 1982;Smith et al 1970), balance (Ehrenberg et al 1991), and sensory and motor peripheral nerve dysfunction Langolf et al 1978;Levine et al 1982;Miller et al 1975;Singer et al 1987).…”

“…Participants were evaluated on a neuropsychologic battery comprising widely used and well-standardized tests. Specific cognitive domains assessed and measures administered were based upon reports of neuropsychologic impairments in occupational studies (Albers et al 1988;Echeverria et al 1995;Langolf et al 1978;Ngim et al 1992;Ritchie et al 1995;Roels et al 1982;Smith et al 1970Smith et al , 1983. Specifically, verbal memory, nonverbal memory, attention, and fine motor coordination were assessed.…”

Epidemiological surveillance of employees in a mercury thermometer plant: An occupational health study

“…Piikivi et al [24] CNS and Kidneys HgU > 50 µg/g creatinine Roels et al [25] whose HgU had exceeded 500 µg/L in the previous year.…”