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Abstract: Objectives: To examine mercury (Hg) and selenium (Se) levels in autopsy samples from a thermometer worker who had been exposed over a long period to, and monitored for, mercury vapor. Case report: Hg and Se levels were determined using radiochemical neutron activation analysis in a worker who had commited suicide 4 weeks after the end of 14 years of exposure and in an unexposed age-matched referent. Histochemical staining of cerebellum was performed according to the method of Danscher and Schrøder. Results: The Hg concentrations (wet weight) were 25 μg/g in the kidney cortex, 1.2 μg/g in the liver, 0.72 μg/g in the lung, 0.025 μg/g in the testis, and 0.014–0.018 μg/g in the cerebellum (gray matter, dentate nucleus, and white matter). The Se level in the kidney cortex was high, 4.6 μg/g, whereas the concentration detected in the other tissue samples was normal. Light microscopy of the cerebellum was normal, and no histochemical staining for mercury was observed. Autopsy samples from the referent showed low Hg and Se levels consistent with other reports. Conclusions: The observed kidney-Hg, which was 50–100 times higher than that occurring in the general population, is in agreement with previous sparse data from ongoing occupational exposure. The high Se level detected in the kidney indicates coaccumulation with mercury. The low Hg concentration found in the cerebellum was unexpected, since some reports have shown much higher brain-Hg long after the cessation of exposure.

Summary Urinary excretion of beta-hexosaminidase (NAG = N-acetyl-beta-glucosaminidase) and albumin was examined in 41 chlor-alkali workers exposed to inorganic mercury and 41 age-matched controls. Either U-HG or B-Hg levels for these workers were available dating from the 1960s to the present. Increased U-NAG was seen in workers with a U-Hg today of more than 4µg/mmol creat (about 50µg/l; 35 µg/g creat). Multiple linear regression analysis showed that U-NAG was correlated to U-Hg and integrated dose but not to the present B-Hg level. No albuminuria (detection limit 12.5 mg/1) was found in any of the subjects. In a longitudinal study, no decrease in UNAG levels was seen in 15 chlor-alkali workers after their vacation (x = 20 d). In five workers followed for ten months after a short exposure period, no definite time trend could be seen. The results show that there is a slight effect on renal tubules even at rather low levels of exposure to mercury vapour. The clinical significance of the enzymuria levels found here is, however, debatable.

A review of the literature and four case reports are presented. The patients had all been exposed to noise as well as to organic solvents and they demonstrate a much more pronounced sensorineural hearing loss than would be expected from their noise exposure only. In one of the cases a psycho-organic syndrome due to solvent exposure was verified. Audiograms from 32 painters in a shipyard who had been exposed to noise and solvents did not, however, show any clustering of inexplicably pronounced sensorineural hearing losses. With reference to the above cases it is suggested that there might be a possibility of an ototraumatic interaction between solvents and noise. In view of the neurotoxic effects of organic solvents, such an interaction is conceivable.

Blood samples and questionnaire background data were collected from 96 children (age 2–14 years) living in urban, suburban, or rural areas with varying traffic intensity and industrial lead pollution in Uruguay. Spot samples of tap water were collected from the homes of 44 children, and samples of top soil were taken from seven areas. Samples of air-borne dust were collected in central and suburban Montevideo. Blood lead concentrations (B-Pb) in children ranged between 47 and 191 (mean 96) μg/L and exceeded in 36% of the children 100 μg/L, the intervention level adopted by the United States Centers for Disease Control. Lead in tap water ranged from 0.2 to 230 (mean 15) μg/L and exceeded in 39% of the samples the maximum level recommended by WHO, 10 μg/L. Lead pipes were used in parts of the water supply systems. Lead in air varied between different locations from 0.15 to 1.7 μg/m3, highest in the very center of Montevideo. The median soil lead ranged from 6 to 2100 μg/g and was highest in industrially polluted areas. At multiple regression analysis, B-Pb was significantly associated only with age (P= 0.032) and traffic intensity at school (P= 0.045). No significant impact on B-Pb of lead in water or soil could be established.

A review of the literature and four case reports are presented. The patients had all been exposed to noise as well as to organic solvents and they demonstrate a much more pronounced sensorineural hearing loss than would be expected from their noise exposure only. In one of the cases a psycho-organic syndrome due to solvent exposure was verified. Audiograms from 32 painters in a shipyard who had been exposed to noise and solvents did not, however, show any clustering of inexplicably pronounced sensorineural hearing losses. With reference to the above cases it is suggested that there might be a possibility of an ototraumatic interaction between solvents and noise. In view of the neurotoxic effects of organic solvents, such an interaction is conceivable.