MERCURY CONCENTRATION IN BLOOD AND URINE OF WORKERS IN SMALL PLANTS MANUFACTURING MERCURIAL THERMOMETERS
1972 Volume 14 Issue 5 Pages 455-461
Details
1972 Volume 14 Issue 5 Pages 455-461
The results of our study on the method of evaluating mercury in man's urine and blood with reduction-aeration procedure are reported in this paper as well as the results of our investigation on chronic mercurial poisoning in workers employed by a small-scale manufacturer of thermometers.
1. Mercury in the urine was determined in the following way. Add excess cystein and stannous chloride to the urine sample, and then alkalize this mixture with NaOH solution. Take the resultant mercurial vapor into a quartz absorption cell and evaluate with the atomic absorption spectrophotometer. With this method it was possible to detect as small an amount as 0.05 μg of mercury in the sample and this procedure proved to be much simpler than others and the results obtained were less variable than those obtained with the method which involved oxydation of the sample urine with potassium permanganate.
2. Mercury in the blood was determined by the following procedure. About 10 g of the whole blood was deproteinized three times with 20 ml of cystein being given 5 per cent trichloroacetic acid. This makes the mercury to be extracted. The supernatant of this was used as a test sample, and the mercury was determined with stannous chloride and NaOH solution as in the case of mercury evaluation of the urine. The recovery rate of mercury with this method was 100 per cent.
3. The amount of mercury in the urine samples taken from normal subjects was in an average 3.5±2.3μg/l and the amount of mercury in the blood samples of normal subjects averaged 0.9±0.6 μg/100g.
4. Of 47 workers of investigated 14 factories manufacturing mercurial thermometers of ordinary type, 13 subjects showed more than 300 μg/l mercurial content in the urine and 5 subjects showed the blood values over 10 μg/100g. Two subjects showing a high level of mercurial content in the blood had such signs of chronic mercurial poisoning symptoms as tremor and scanning speech.
5. In five factories manufacturing special type of mercurial thermometers, such as maximum and minimum thermometers, Beckman's differential thermometers, dial thermometers, etc., there was no subject that showed more than 300 μg/l mercurial content in the urine. However, in some of the workers who had served long years the blood showed values over 10 μg/100 g in mercurial content.
