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T Norseth

Publications and source records attributed to T Norseth.

At least 55 records · Page 3Linked to original sources
PubMed1975

Dose-dependence of methylmercury metabolism. A study of distribution: biotransformation and excretion in the squirrel monkey.

The distribution and excretion of different body burdens of methylmercury (MeHg) have been investigated in the squirrel monkey. In monkeys given weekly 0.8 mg/kg doses, orally, of 203-MeHg, a linear correlation was observed between the concentrations of radioactive Hg in the blood and brain to as much as a blood concentration of 1 mug/gm. Above this level, the ratio of concentration in the brain and blood was increased. The total Hg concentration in bile collected from the bile duct was 10% to 30% of that in blood, while the concentration in bile from the gallbladder approached that in the blood. The total Hg concentration in feces was always more than ten times that in urine. Biotransformation of MeHg to inorganic mercury has been demonstrated; in the liver about 20% of the total mercury was inorganic, in the kidney 50%, and in the bile 30% to 85%. In the brain less than 5% of the total mercury was inorganic. After a single 0.8 mg/kg dose, orally, of 203-MeHg, the halftime for total Hg in blood was 49 plus or minus 2.8 days, and in the whole body 134 plus or minus 2.7 days. During the first four days after dosing, the decrease in blood concentration was more rapid than that occurring later, due to a redistribution within tissue compartments. A differential distribution of MeHg within the brain has been demonstrated in animals that showed clinical signs of intoxication.

Animals↗
PubMed1975

A cohort study of bronchial carcinomas in workers producing chromate pigments.

A cohort study of the incidence of bronchial cancer in male workers in a small company producing chromate pigments is presented. Altogether 133 workers had been employed by the company from the time production was started in 1948 until the end of 1972. Workers with more than three years employment were included in the study, and three cases of bronchial carcinoma were found among the 24 workers who fulfilled this requirement. Based on the data of the Cancer Registry of Norway the risk of bronchial cancer for a corresponding group of the general population was found to be 0.079, which gives a risk ratio for exposed workers of approximately 38. The average age of the cancer patients was as low as 50 years at the time of diagnosis. All workers in the company had been exposed mainly to zinc chromate dust, and the exposure levels of the workers developing bronchial cancers had probably been from 0-5 to 1-5 mg Cr/m-3 for six to nine years. Two of the three patients were smokers. It is assumed that exposure to chromate pigments, and probably to zinc chromate, may be related to the increased incidence of bronchial cancer in this group of workers. The possibility of a contributing effect of tobacco smoking in at least two of the three cases cannot be ruled out.

Adult↗