Åke Swensson

Studies in Humans on the Distribution of Mercury in the Blood and the Excretion in Urine after Exposure to Different Mercury Compounds

Using neutron activation analysis the mercury concentration in blood of non-exposed control persons has been shown to be 6–12 ng/g. In a group of persons exposed to methyl mercury compounds the mercury content in whole blood was 70–180 ng/g, in plasma 3–10 ng/g. A group of persons exposed to metal mercury vapors had a mercury concentration in whole blood of 12–90 ng/g, in plasma 5–74 ng/g. The mercury concentration in urine was hardly increased in the alkyl mercury group but there was a fair increase in the metal mercury group.It is evident that the distribution of mercury in blood is quite different after exposure to different mercurials and so is the rate of excretion in urine. The distribution-excretion pattern may be used for diagnostic purposes.The excretion of mercury cannot be used to evaluate the exposure to alkyl mercury compounds.

Methylmercury compounds in eggs from hens after oral administration of mercury compounds.

White leghorn hens were fed for 140 days with wheat treated with methylmercury hydroxide, phenylmercury hydroxide, methoxyethylmercury hydroxide, and mercury(I1) nitrate. The daily administration was 400 or 1600 pg. of mercury. After administration of phenylmercury hydroxide, methoxyethylmercury hydroxide, or mercury(I1) nitrate, a proportion of the mercury was transformed to methylmercury compounds. The organs of the hens and the eggs contained different levels of methylmercury compounds. Since the methylation of mercury in the hen is neither rapid nor complete. the level of mercury concentration in the organism of the hen and in the eggs is mainly determined by the rate of excretion of the actual mercury compound administered.

Cyanide and Thiocyanate Levels in Blood and Urine of Workers with low-grade Exposure to Cyanide

SummaryThe concentrations of free cyanide in the blood and in the urine, and the levels of “free” thiocyanate (oxidized to cyanide and distilled) as well as “total” thiocyanate (directly determined and quite unspecific) were determined in the urine of 140 volunteers.There were four main categories of volunteers: (i) non-smokers, not exposed to cyanide in the atmosphere, (ii) smokers, not exposed to cyanide, (iii) non-smokers, exposed to various levels of cyanide in their occupation, and (iv) smokers who were also exposed to cyanide.The cyanide concentration in the blood did not show a clear relationship to either smoking or moderate occupational exposure; the levels were found to lie between 2.0 and 15.0 Μg of free cyanide per 100 ml of blood, with an average of 5.4 Μg for all categories of volunteers.It was found that the individual concentrations of free CN′ and CNS′ in the urine varied considerably and could not be used for detecting undue chronic exposure to cyanide at the concentrations encountered in the atmosphere. The average values, on the other hand, varied in a regular pattern for each of the four categories listed above. The influence of smoking had a far greater effect on the values obtained than the influence of atmospheric cyanide.Because of the great variations caused by other factors, concentrations of CN′ and CNS′ in the urine are not appropriate tools for individual routine control of minor occupational exposure to cyanides. However, non-smokers exposed to moderate cyanide levels in the air, and any individual exposed to high cyanide levels show higher than average values of CN′ and CNS′ in their urine.The cyanide values reported in this paper may be useful for the evaluation of analytical results from individual cases where poisoning from cyanide in the atmosphere is suspected.

Aluminium dust pneumoconiosis a clinical study

SummaryIn connection with the discussion of five cases of pneumoconiosis occurring in an aluminium powder mill the authors refer to the possibility of aluminium dust pneumoconiosis being a distinct disease entity. The cases under review have been followed up to 7 years after the first positive X-ray picture. The progress of the disease seems to be initially rapid, but if exposure ceases it seems to be arrested after some time. In mild cases the symptoms may regress. In severe cases the changes in the lungs may cause an increased load on the right ventricle, ultimately leading to failure. Not even in these severe cases is there evidence of continuous progress of the changes in the lungs.

Effect of BCG on Lymphatic Lung Clearance of Dusts With Different Fibrogenicity

The transport of titanium dioxide, amorphous silica, heated amorphous silica, and quartz from the lungs to the hilar lymph nodes, and the weight reaction of these organs, were studied on BCG-treated and control rats. BCG treatment increases the retention in the lungs of all the dusts studied and decreases it In the hilar lymph nodes. Thus, the dust transport from the lungs via the lymphatics is obliterated by BCG, and both “inert” and fibrogenic dusts are, to a significant degree, transported by this route. The combined effects of BCG and fibrogenic dusts tend to be more pronounced in the lungs and less pronounced in the hilar lymph nodes than the sum of the separate BCG and dust effects.

TISSUE REACTION TO DIFFERENT TYPES OF AMORPHOUS SILICA

Abstract The tissue reaction has been studied, in the lungs and hilar lymph nodes of rats, after single intratracheal injections of 40 mg of different samples of amorphous silica suspended in physiological saline. The reaction has been compared both with the reaction caused by the injection of 40 mg of quartz particles, and with the organs of the control rats. The fibrogenic potency of different types of amorphous silica is different. Within the first month the tissue reaction may be more intense or much smaller than after injection of quartz. There may or may not be a tendency to progression. When kieselguhr containing no crystalline components is heated to 800 °C for 24 hr its fibrogenic tendency increases markedly although this heating is insufficient to cause demonstrable transformation to crystalline silica forms. Thus, in the animal experiment, it is possible to demonstrate that there are different types of amorphous silica as regards their fibrogenic potency.

Survival of BCG in rat tissues

SummaryCulture on Löwenstein medium shows that lungs, hilar lymph nodes and spleens from female albino rats injected intravenously with BCG, and then killed after observation periods up to 12 months, contain viable BCG. These organisms induced granulomatous tissue reactions in rat lungs, indicating that the resistance of rats to tubercle bacilli is only relative.

Tierexperimentelle Untersuchungen über den Staub in der Arbeitsatmosphäre von Ferrosiliziumwerken

Bei der Herstellung von Ferrosiliziumlegierungen wird unter anderem freies Siliziumdioxyd in Form von Quarz verwendet. Wahrend des Prozesses, der bei einer Temperatur von etwa 2000° C ablauft, geht 20-30% der zugefuhrten SiO2-Menge mit dem Rauch ab, wo sie als feinpartikulares amorphes Siliziumdioxyd wieder gefunden wird.