Absorption and Excretion of Mercury in Man

The recent literature dealing with mercury in urine of humans has been reviewed and some new data have been developed. On a group basis, there appears to be good correlation between levels of mercury exposure and levels of urinary excretion. This relationship does not always hold for an individual. There is no clear-cut evidence that workers presumed to have unchanged conditions of exposure will show either an increase or decrease in urinary mercury as duration of exposure increases. Levels of mercury in the urine show little or no correlation with manifestation of poisoning. There appears to be no level above which symptoms cannot occur. The empirical use of arbitrary levels in control programs may result in the imposition of unnecessary restrictions. Present evidence suggests that mercury can be found in 20% of ''normal'' urines. Concentrations up to 100..mu..g/liter or more have been found but rarely is the figure greater than 50..mu..g/liter. Wide fluctuations in the hourly and daily excretion of mercury in urine are common in exposed persons. Present knowledge does not justify the application of specific gravity corrections to mercury in urine.