Effect of occupational mercury exposure on plasma lysosomal hydrolases

Abstract

The activities of three plasma lysosomal hydrolases, beta-galactosidase, beta-glucuronidase and beta-N-acetylglucosaminidase, were studied in 20 workers exposed to metallic mercury vapor in a chlorine alkali plant and in 10 nonexposed referents. The urinary excretion and blood levels of mercury were determined on the day of study, and the history of mercury exposure was reviewed from the records of mercury concentrations in urine and blood over periods of up to 133 months. The average levels of beta-N-acetylglucosaminidase and beta-glucuronidase were higher in the plasma of exposed workers, but the difference was not significant. No significant positive correlation was seen between lyosomal enzyme activities and cumulative long-term exposure to mercury. It is concluded that measurement of plasma lysosomal hydrolase-activities is not of great value in the biological monitoring of workers exposed to low concentrations of metallic mercury vapor. In line with published data, the concentration of mercury showed a clear-cut diurnal variation in nonexposed persons, persons currently exposed and persons with a history of past exposure. The excretion rate of mercury remained constant throughout the day.

Estimation and validation of mercury intake associated with fish consumption in an EPIC cohort of Spain

“…We lacked statistics on the number of dental fillings in individuals in the sample, which prevents us from adjusting for this variable. Nevertheless, it has been suggested that there is not sufficient evidence that methylation of inorganic mercury is produced in live human organisms 39 , in spite of the fact that some studies 985 Mercury uptake and fish consumption do indicate this 40,41 . Furthermore, methylmercury may undergo a low-intensity process of demethylation and turn into inorganic mercury.…”

Mercury Toxicity and Treatment: A Review of the Literature

“…It is important to recall that blood, hair, and urine mercury levels reflect recent exposure and do not correlate with total body burden [83–86]. Blood and urine levels correlate fairly well to each other, but not to total body burden [87].…”

Mercury exposure of different origins among dentists and dental nurses.

“…The subjects were instructed to collect all voided urine during exactly 24 h. The total mercury content of a 24-h urine sample was used for calculating the current excretion rate, which has been shown to be a stable biological index of mercury exposure (17,18).…”

“…The only study found using the urinary excretion rate of mercury for estimating mercury exposure was that of Aitio et al (17). For a reference group of 10 individuals a mean excretion rate of 2.4 ug Hg /24 h was reported.…”