Avoidance of contamination in element analysis of serum samples.

The selection of sampling needles and plastic material used for the storage of serum samples were studied. Sampling needles and plastic material were analyzed by neutron activation analysis. Leaching of elements from containers by acids and EDTA-solution was also followed. Also the long-term storage of serum samples for element analysis was investigated. Zn, Cu and Se concentration of serum was followed over the course of four years. The selection of sampling needles, as well as all plasticware which comes into contact with the serum, should be based on the knowledge of possible removal of elements from materials into the sample. Storage of serum samples at -18 degrees C does not change the copper, zinc or selenium concentration over the course of 4 years despite repeated melting and refreezing of the samples.

Element concentrations in serum, erythrocytes, hair and urine of alopecia patients.

The trace element concentrations of Se, Rb, Zn, Fe, Co, Cs, Mg, Ca, F, Cu, Cr and Ag in serum and of Se, Rb, Zn, Fe, Co and Cs in red cells of Finnish alopecia patients were determined. In addition the Cu and Zn content in 24 h urine and Cu, Zn, Cd, Cr and Se concentrations in the hair of these patients were studied. No differences in element concentrations of the samples mentioned above as compared to those of the normal population could be found. In addition, there was no tendency of excesses or deficiences of elements analysed in the samples. Statistically significant difference was found between the copper content of serum in alopecia areata and alopecia universalis patients and also between the copper content of serum in alopecia areata plus alopecia totalis and alopecia universalis patients. The selenium concentration in serum samples of a few patients was low, but this is in agreement with the fact that the selenium content in the Finnish population is low due to the scanty content of selenium in food.

Retention and clearance of stainless steel shieldgas welding fumes in rat lungs.

The use of metal inert gas (MIG) stainless steel (SS) welding techniques is rapidly increasing. The possible health hazards of MIG/SS welding fumes are not known; more attention has been paid to manual metal arc (MMA) welding. In this study, 52 male Wistar rats were exposed to MIG/SS welding fumes generated by an automatic welding device for "nose only" exposure. For the retention study, the duration of exposure was one hour per workday for 1,2,3, and 4 weeks. For the clearance study, the duration was 4 weeks, and the follow-up period was 106 days. The retention and clearance of the alloyed metals of SS (chromium (Cr), manganese (Mn), nickel (Ni] and iron were studied in the rats' lungs, and the results were compared with the corresponding results of MMA/SS welding. The multielement chemical analysis was made using instrumental neutron activation analysis (INAA); the concentration of exogeneous iron (Feex) was determined by a magnetic measuring method. Feex and Cr were retained in the ratio expected; Mn, Ni and total Fe were retained slower than expected. The total Fe did not clear at all even though Feex cleared with the half-time of 50 d which corresponded well with that of pure magnetite. The accumulation of Cr in the lungs was very high: it cleared with the half-time of 240 d. The clearance patterns of Mn and Ni were very similar. They followed a double exponential model with half-times of 2 d and 125 d for Mn, and 3 d and 85 d for Ni. The results indicated that even though the retention patterns for MMA and MIG welding fumes were very similar, the clearances differed very much.

Stainless steel manual metal arc welding fumes in rats.

Forty two male Wistar rats were exposed to manual metal arc (MMA) stainless steel (SS) welding fumes generated by an automatic welding device for "nose-only" exposure. The exposure simulated an actual MMA/SS welding environment as closely as possible. For the retention study, the duration of exposure was one hour per workday for one, two, three, of four weeks and for the clearance study four weeks. The retention and clearance of the chromium, nickel, and iron found in MMA/SS welding fumes in the rats' lungs were studied as was the distribution of the metals to other organs. Instrumental neutron activation analysis (INAA) was used for the multi-element chemical activation analyses. The concentrations of chromium and nickel in the blood and the urine were determined by atomic absorption method (AAS). The retention of exogenous iron was determined by a magnetic measuring method. The results indicated that the lungs were the target organs of soluble hexavalent chromates. The half times of lung clearance for Cr, Ni, and Fe were 40 +/- 4 d, 20 +/- d, and 50 +/- 10 d. When the lung clearance curves are compared, the half times of Cr and Fe lung clearance are similar but nickel disappears faster. The distribution and clearance patterns of chromium to other organs differ from those obtained after single intravenous or intratracheal injections of alkaline chromates.

Comparison of the behavior of stainless and mild steel manual metal arc welding fumes in rat lung.

The lung retention and clearance of manual metal arc (MMA) stainless steel and mild steel welding fumes were determined in the rat. The exposure simulated the actual welding situation. The duration of exposure in the "nose-only" exposure chamber was 1 h/workday for one, two, three, or four weeks in the retention study and for four weeks in the clearance study. The concentration of exogenous iron was determined by the magnetic measuring method. Instrumental neutron activation analysis was applied to determine the concentration of total iron, chromium, and nickel in the lungs. The results indicated that the lung retention and clearance patterns for the two types of welding fumes were different. A linear relationship was observed between the amount of stainless steel MMA welding fume retained in the lungs and the duration of exposure, whereas the retention of mild steel MMA welding fume in the lung was saturated as a function of the cumulative exposure time rates. The maximum amount of lung-retained contaminants was 880 micrograms for stainless steel MMA welding fume and 220 micrograms for mild steel MMA fume.

Amount and distribution of fume contaminants in the lungs of an arc welder post mortem.

This study describes various post-mortem examinations of the lungs of a shipyard arc welder. These investigations comprised morphological methods, including gross pathology and radiography, histological and ultrastructural examinations, chemical analysis of lung tissue, and sensitive magnetic measurements, which can now be used to detect magnetic contaminants, such as welding fume, in human tissue. Such methods can also show the distribution of contaminants. The amount of welding-fume contaminants was low, only 110 mg. The contaminant iron seemed to represent only 10% of the total iron chemically analysed in lung tissue. The concentration of the total iron was 4-10 times higher than that in control tissue. Contaminants tended to collect in the central areas of the lungs. Two concentration centres could be observed in each lung, one anterior and one posterior. There was slight fibrosis around pigmented areas. Histological findings were similar to those of previous studies. Transmission electron micrographs showed that enlarged lysosomes of macrophages contained electron-dense granules, 450 nm to less than 5 nm in diameter, which formed aggregates and short chains, and resembled welding-fume particles in the breathing zone. Our results show the value of studying the same material by a number of inter-related methods.

Mineral composition of enamel and dentin of primary and permanent teeth in Finland.

The concentrations of 12 different elements were measured in dentin and enamel of primary and permanent teeth collected in six different localities in Finland. Na, Cl, Al, Mn, Ca, and P were determined by neutron activation analysis, K, Mg, Zn, Cu, and Fe by the atomic absorption method, and F with the fluoride-specific electrode. Most elements were present in higher concentrations in the enamel than in the dentin: Mg, however, was higher in the dentin. Compared with the permanent teeth, the primary teeth contained more K and Mn in enamel and K and Mg in dentin, but less Na and Zn in enamel. Differences between the six localities were significant for F, Cl, K, Zn, Na, and Mn. Fe, Cu, and Mn contents of teeth were much lower in Finland than elsewhere; in the typical Finnish diet the contents of Fe and Cu are relatively low and iron deficiency anemia is usually common in Finland.

Distribution of an adenohypophysial constituent in the body. II. Quantitative tissue distribution in the rat.

A peptide with a molecular weight of about 5000 has previously been shown to affect the output of semen in frogs and probably also in mammals. This sperm-releasing substance is not part of any known gonadotropic hormone. The tissue distribution of this substance has been investigated. The iodinated substance has been injected into rats and the radioactivity content of the different tissues has been determined. Iodinated rat albumin has been injected into other rats, to determine the content of blood in the different tissues. A formula has been derived to obtain a figure for real accumulation, using the radioacitivity content of the blood and of the tissues after injection of the sperm-releasing substance and albumin, respectively. The sperm-releasing substance is incorporated into the adenohypophysis, neurohypophysis, liver, kidney, lung, ovary, uterus and some male sexual organs. The causes for this distribution are discussed.

Distribution of an adenohypophysial constituent in the body. I. Wholebody autoradiographical studies in the mouse.

A peptide with a molecular weight of about 5 000 has previously been shown to affect the output of semen in frogs and probably also in mammals. This sperm-releasing substance is not part of any known gonadotropic hormone. The distribution of this substance has been investigated using whole-body autoradiography. Radioactive material is incorporated into the epididymis, the adenohypophysis and probably also into the ovary.