Pirkko-Liisa Kalliomäki

Cadmium and chromium as markers of smoking in human lung tissue.

The pulmonary cadmium (Cd) and chromium (Cr) contents from 45 decreased persons from Northern Finland were determined by plasma emission spectrometry (DCP-AES). These subjects did not have any malignant diseases or known occupational exposure to heavy metals. The pulmonary metal concentrations were compared with smoking history, pulmonary emphysema, age, and occupation. The mean Cd concentrations for the nonsmokers, smokers, and exsmokers were 0.4 (SD +/- 0.4), 3.0 (SD +/- 2.2), and 1.1 (SD +/- 1.0) micrograms/dry wt, and the corresponding values for Cr were 1.3 (SD +/- 0.9), 4.3 (SD +/- 3.3), and 4.8 (SD +/- 4.0) micrograms/g dry wt, respectively. The pulmonary Cr content increased with age and smoking time, but showed no connection with occupation. The Cd content was dependent only on smoking-related variables, increasing with the amount of tobacco smoked. The pulmonary Cd was seen to return to the level of nonsmokers in 21-22 years after cessation of smoking, whereas Cr showed no decreasing tendency with the time since smoking stopped.

A study of the chemical structure of particles in the welding fumes of mild and stainless steel

Abstract The chemical surface structure of three types of welding fumes-manual metal arc and metal inert gas welding fumes of stainless steel and manual metal arc welding fumes of mild steel-were analyzed. The semiquantitative analysis and oxidation states of the surfaces of iron, manganese, chromium and nickel were carried out by X-ray photoelectron spectroscopy. XPS measurements and ion bombardment were combined to study changes in the concentrations and oxidation states in the direction perpendicular to the surface of the fume particles.

Measurement of lung-retained contaminants in vivo among workers exposed to metal aerosols

In Finland the amount of lung-retained contaminants has been measured among welders, foundry workers, and iron and steel factory workers. About 300 subjects have so far been measured since 1976. The method of measuring is based on the magnetic properties of metal aerosols. At the very beginning the method resembled the one suggested by D. Cohen. The original method was too slow, and data processing was not suitable for clinical or hygienic work. Therefore, the automatic and computerized instrument for measuring lung-retained contaminants was developed in cooperation with Outokumpu Oy. The resolution of the magnetic measurement is better than 0.05 nT corresponding to a sensitivity of 0.5 mg of magnetic contaminants in the lung in the form of magnetite. These figures mean that, in practice, a shipyard welder has enough contamination for measurement after one months exposure. In addition, the present paper reviews the magnetic properties of metal aerosols briefly and summarizes the results of measuring different occupational groups.

High concentrations of chromium in lung tissue from lung cancer patients.

The pulmonary chromium content was determined by plasma atomic emission spectrometer (DCP‐AES) from 53 lung cancer and 43 control patients, and compared with smoking habits, severity of emphysema and occupational history. The chromium content from the lung cancer patients was higher than that from the smoking (P < 0.025) or nonsmoking control patients (6.4 ± 4.3, 4.0 ± 4.0, and 2.2 ± 0.6 μg/g dry weight, respectively). A positive correlation between the pulmonary chromium and smoking time (P < 0.025) and the severity of emphysema (P < 0.001) was found in the control but not in the cancer patients. The difference in the pulmonary chromium content was greatest between those lung cancer and control patients who were light smokers or had mild emphysema. This group of lung cancer patients included subjects with occupational exposure to chromium. The possibility of occupational cancer should be considered especially with light smokers. The grade of emphysema and metals such as chromium accumulating from tobacco could serve as objective indicators of smoking.

Cytotoxic effects of four types of welding fumes on macrophages in vitro: a comparative study.

The effects of fume particles given off by the manual metal arc (MMA) and metal inert gas (MIG) welding of stainless steel (SS) and mild steel (MS) were studied on rat alveolar macrophage cultures in vitro. The fumes were generated by welding, and particulate material obtained was collected on membrane filters. The macrophage cultures were exposed to the total dust and to its water-insoluble fractions. Cell variability and the release of both lactate dehydrogenase and one lysosomal enzyme from the cells to the medium were measured after an exposure period of 24 h. The cytotoxic control dust was DQ 12 quartz, and the inert control dust was pure titanium dioxide. According to the parameters studied, SS/MMA and MS/MMA welding fumes were cytotoxic to rat alveolar macrophages. The cytotoxic effect of SS/MMA welding fumes decreased after the samples had been washed with phosphate-buffered salt solution. The MIG welding fumes of SS and MS had markedly smaller effects on the cells. Diluted solutions of potassium chromate were also tested in order to investigate its role in the cytotoxicity of SS/MMA welding fumes. The results suggest that hexavalent chromium may be responsible for the cytotoxicity of SS/MMA.

Estimation of individual dust exposure by magnetopneumography in stainless steel production

The objectives of the study were to measure the magnetic dust lung burden of workers in stainless steel production by magnetopneumography (MPG) and to investigate the relationship of the results with air-borne concentrations of dust, total and hexavalent chromium as well as urinary excretion of chromium. There were 128 workers from the chromite mine, sintering plant, ferrochrome smelter, stainless steel smelting shop, cold rolling mill and welding shop in the exposed groups and five persons from the office staff in the control group. The remanent magnetic field (RMF) in the lungs was slightly elevated among workers in the ferrochromium and steel smelting shops; the levels were, however, lower than those reported for welders earlier and those observed in the welding/repair shop. Workers in the mine, concentrator and sintering plants and in the cold rolling mill exhibited remanent magnetic fields comparable to the referents. There was a relationship between the RMF and the actual urinary chromium concentration. Miners and concentrator and sintering plant workers showed retarded relaxation rate (ReR) of the remanent magnetic field. However, the RMF of the first two of these groups were low (< 0.1 nT) and this made it difficult to measure the ReR accurately. The duration of exposure correlated weakly but significantly with the relaxation rate, while smoking was not related to it.

Cobalt in hard metal manufacturing dusts

Cobalt containing airborne dusts from hard metal manufacturing and grinding processes were analyzed by atomic absorption spectroscopy and instrumental neutron activation analysis. The structure of the dusts was studied using scanning electron microscopy with energy dispersive X-ray detector. Cobalt was found to exist as separate particles only in the dust from the mixing of raw material powders. In the dusts from the pressing, forming and grinding of hard metal cobalt seems to appear mainly in contact with tungsten carbide particles. The dusts contained 5–10% of cobalt and 60–80% of tungsten in different phases of the process. The specific remanont magnetic moment of the dusts was measured and it ranged from 0.6 to 1.1 Am2/kg. In these dusts cobalt is the magnetic component. The content of ferromagnetic α-Co in the dusts from the different process stages is sufficient for the measurement of lung-retained contaminants in vivo among hard metal workers.

A microcomputer-controlled rotating-sample magnetometer

A microcomputer-controlled, automatic rotating-sample magnetometer is constructed for measuring the specific remanent magnetic moment and pulse coercive force of a ferro/ferrimagnetic dust sample. The sensor of the magnetometer consists of an iron-cored coil with an air gap in which the sample rotates inducing a voltage proportional to its magnetic moment. Another coil is used to magnetise or demagnetise the sample using a short pulse. All measurement steps are performed automatically and rapidly under computer control without any need to touch the sample holder. The construction and interface circuits of the magnetometer are described and some test results presented.