PubMed Health⌕ Search

Biomedical subjects

E Wiecek

Publications and source records attributed to E Wiecek.

At least 37 records · Page 2Linked to original sources
PubMed1991

Biological activity of synthetic amphibole asbestos.

The carcinogenic and fibrogenic activity of four samples of synthetic amphibole asbestos with different chemical structure was examined in white rats. Pleural mesotheliomas were found: in 11 out of 27 rats (37.8%) treated with magnesium asbestos; in 4 out of 24 animals (6.7%) for nickel asbestos; 13 out of 22 (59.1%) for cobalt asbestos; and in the experiment with asbestos where germanium was substituted for silicon pleural mesotheliomas were observed in 2 out of 55 rats (3.6%). No tumours of this kind were found in the control group. As revealed by the study results, all the examined samples of synthetic amphibole asbestos exhibited carcinogenic potentials. Correlation between the carcinogenic and fibrogenic activity could also be observed. The replacement of silicon with germanium produced considerable decrease in the carcinogenic and fibrogenic potentials of asbestos.

Animals↗
PubMed1991

[Occupational exposure to asbestos-containing dust at the plants manufacturing and using asbestos products during the years 1986-1989].

During 1986-1989, dust levels at workplaces in 19 plants manufacturing or using asbestos products in Poland were measured. Total dust concentrations were determined by the gravimetric method and respirable asbestos fibre concentrations were determined by the phase contrast optical microscope method (PCOM). Air was sampled at the breathing zones of the workers by using Casella personal air samplers. Average respirable asbestos fibre concentrations at the workplaces were from 0.06 fibre/cm3 (control desk operator) to 2.25 fibre/cm3 (spinning machine operator), and the average total dust concentrations were from 0.7 mg/m3 (technicians) to 2.3 mg/m3 (preparatory department workers). Compared with the 1980-1985 period, total dust concentrations were 1.5 times, and respirable asbestos fibre concentrations 2.9 times lower. Considering the obtained data and the analysis of the occupational diseases in workers exposed to asbestos dust during 1983-1988, the national expert group for industrial dusts has suggested that the MAC values for chrysotile dusts be lowered to 1.0 mg/m3 (total dust) and 0.5 fibre/cm3 (respirable fibre).

Air Pollutants, Occupational↗
PubMed1991

[Evaluation of occupational exposure of workers engaged in mining of rock raw materials in the Sleza massif].

In two serpentinite mines and in a factory producing asphalt pavements using serpentinite, exposure to dusts and polycyclic aromatic hydrocarbons (WWA-fraction soluble in benzene) was assessed. In rock samples taken in the serpentinite mine and in dust samples from work posts crystalline phases were determined (using X-ray radiography and spectrometry in infrared). Also, morphology of dust particles was performed using electron microscopy. Both in the rock samples and in dust fibrous antigorite, a mineral of strong cancerogenic properties, was found. Total dust concentrations varied between 1.05 and 280 mg/m3, concentration of respirable mineral fibres from 0.01 to 3.56 fibre/cm3, and concentration of aromatic hydrocarbons varied between 266.7 and 850 micrograms/m3. The study will be continued concerning evaluation of biological effect of serpentinite in animal experiments and assessment of extraoccupational exposure of people living in the neighbourhood of serpentinite mines and plants processing this mineral.

Air Pollutants, Occupational↗
PubMed1989

[Volatile ashes and their biological effect. 2. Fibrogenic effect of volatile ashes].

In experiments on white Wistar rats fibrogenic effects of 6 samples of fly-ashes collected from electric precipitators in power engineering plants have been evaluated. The coal came from different national deposits. All the ashes have been found to contain: quartz and mullite, 3 ashes contained additionally orthoclase, whereas 1, apart from quartz and mullite, contained kaolinite; naturally radioactive elements (Ra226, K40, Th228) and trace elements (As, Ba, Be, Cd, Ce, Cu, Fe, Pa, Mo, Ni, Pb, Se, U Zu). Experimental pneumoconiosis was induced through intratracheal administration of single doses of 50 mg of dust; the experiment was carried out at 3 time intervals of 3, 6 and 9 months. The fibrogenic activity was evaluated both qualitatively (histopathological methods) and quantitatively (lung weight, hydroxyproline content in lungs, dust elimination from lungs); control groups consisted of animals which obtained NaCl solution and quartz sands. Fly-ashes were found to exhibit different fibrogenic effects, yet, their fibrogenic activity was weaker, compared to quartz sands. No clear correlation was found between fibrogenic effects of ashes and test physico-chemical properties, such as the content of SiO2, trace elements or naturally radioactive elements. Analysis of occupational diseases (for the period section): (1979-1983) demonstrated occupational diseases of dust-related aetiology among power engineering workers, pneumoconioses, constituting 7.8% of 127 cases of occupational diseases.

Animals↗
PubMed1988

[Fly ash and its biological effects. I. Production, utilization and physico-chemical properties of fly ash].

The paper includes the results of Part I of the studies designed to evaluate occupational risk of power engineering workers, i.e. people employed in plants producing fly-ashes, as well as those working in lightweight concrete plants where fly-ashes are applied as raw materials. The authors have found out that fly-ashes included mainly quartz, orthoclase and mullite. In dust samples, particles of fibrous structure have been found (probably--mullite). The content of free crystalline silica came to 31.6% in total dust and 8.9% in respirable dust. Fly-ashes contained:--naturally radioactive elements K40, Ra226, Th228 (maximum values were, respectively: 1070 Bq/kg, 222 Bq/kg, 142 Bq/kg of dust),--aromatic hydrocarbons (benzene-soluble fraction) in the amount of 0.001 to 0.003 microgram/mg, as well as admixtures of heavy metals in amounts varying largely. The dust concentrations at workplaces ranged from 1 mg/m3 to 200 mg/m3, depending on the type of work (inspection, repair of boilers). The results demonstrate that in the working environment of power engineering and lightweight concrete plants there occur agents of potentially fibrogenic and cancerogenic properties.

Air Pollutants, Occupational↗
PubMed1987

[Evaluation of the work environment in factories producing artificial mineral fibers (MMMF)].

In seven MMMF producing plants, workplaces have been evaluated through measurements of the concentrations of the total dust and respirable fibers of over 5 micron length and below 3 micron diameter, using personal dosimeters of Cassella firm. Only in one of the plants the time weighted average concentration of total dust was 4.11 mg/m3, exceeding the TLV value (4.0 mg/m3). Respirable fibers concentrations ranged from 0.005 to 1.44 fibres/cm3, so in none of the plants the TLV value of 2 fibres/cm3 was reached. The greatest air dustiness was found at mineral wool spreading and breaking workplaces. However, such workplaces occur only in two plants using the oldest technology of MMMF production. Analyses of fibres sizes made with the use of optical and electron microscopy indicated that the contribution of respirable fibres to the total dust weight is slight, up to a dozen per cent.

Air Pollutants, Occupational↗
PubMed1986

[Biological effect of fibrous mineral dust. II. The neurotoxic effect of products of the thermal degradation of chrysotile].

In experiments on animals the effect of heating chrysotile at 600 degrees C upon their biological action has been tested. Three chrysotile samples used in the Polish industry (MX-22 from deposits in Rhodesia, N-239 from Canada and PRZ-1-71 from deposits in the USSR (have been investigated). An X-ray diffraction analysis of heated chrysotile samples exhibited the total lack of lines characteristic for crystal substances in MX-22 and N-239 samples, whereas in the PRZ-1-71 sample the chrysotile content was about 20% of that in a non-heated sample. Intraperitoneal administration of a suspension of 100 mg of the dust brought about nervous system disturbances (shambling, atrophy of the response to ache, drop of internal body temperature and other (and finally-death of all experimental animals. Male rats survived longer from dust administration till the disturbances followed by death, i.e. from 8 hrs to 3 days, whereas female rats survived from 45 minutes to 24 hours only.

Animals↗
PubMed1986

Comparative studies of fibrogenic properties of wollastonite, chrysotile and crocidolite.

Fibrogenous effects of wollastonite, chrysotile and crocidolite have been investigated in experiments on animals. (Wollastonite is a calcium silicate of fibrous structure, occasionally applied as asbestos substitute). The experimental animals were intratracheally administered single doses of 50 mg of the test material suspended in 0.6 ml of physiological NaCl solution. The animals were decapitated 3, 6 and 9 months after the experiment. Fibrogenic properties were evaluated basing on the weight of wet lungs, content of lipids and hydroxyproline in lungs, as well as histopathological tests of lungs, mediastinal lymph nodes and spleen. Histopathological preparations were evaluated using an optical, microscope or transmission electron microscope. The findings of biochemical, pathomorphological, and ultrastructural studies demonstrated slight fibrogenic effects of wollastonite, as compared to chrysotile and crocidolite.

Animals↗
PubMed1986

[Strategies in measuring air pollution in the work environment].

The procedures of measuring the dustiness in the work environment have been discussed, involving short- and long-lasting stationary measurements taken continually during the 8-hour working day with individual samplers. Examples of a statistic treatment of the results and interpretation based on mandatory hygienic standards for industrial dusts have been presented.

Air Pollutants, Occupational↗
PubMed1985

[Polish asbestos and its fibrogenic effect. II. Identification and fibrogenic effect of fibrous minerals occurring in road stone deposits].

Fibrogenic properties of a fibrous mineral occurring in road stone deposits mined at Nasławice at the Lower Silesia have been tested. Diffractometric and infrared absorption spectra tests identified this mineral as antigorite. The content of free crystalline silica was 1.3%. The dust (50 mg) obtained from the test mineral when intratracheally administered to experimental animals as a suspension in physiological NaC1 solution yielded statistically significant increases of the lung weight and hydroxyproline content, as compared to controls. The mean weight of experimental animals' lungs after 3 months was 1898.4 mg, after 6 months--2116.8 mg, after 9 months--2878.4 mg. The control animals' lung weight was 1409.6 mg after 3 months, 1634.4 mg after 6 months and 1939.9 mg after 9 months. Hydroxyproline content in experimental animals' lungs was 5.1 after 3 months, 5.8 mg after 6 months and 8.6 mg after 9 months. In controls, hydroxyproline content in lungs was, respectively: 3.5; 3.9 and 4.0 mg after 3, 6, and 9 months of the experiment. However, the process of lung fibrosis when affected by antigorite from Nasławice was slower than under effects of antigorite from Szklary, which may result from almost 10 times fewer numbers of fibrous particles in the dust obtained from antigorite from Nasławice.

Animals↗
PubMed1985

[Biological effect of fibrous mineral dust. I. Fibrogenic properties of the products of the thermal degradation of chrysotile].

Chrysotile asbestos samples, on comminution, were exposed to temperatures typical for asbestos products exploitation. Subsequently, in an experiment on white rats the effects of temperature upon asbestos fibrous effects were evaluated. The highest aggressiveness was that of the sample heated at 600 degrees C. All the animals died as soon as 50 or 25 mg of dust had been administered intratracheally. Only 3 samples could be administered intratracheally at a dose of 50 mg: non-heated. heated at 400 degrees C and heated at 800 degrees C samples. The doses heated at 400 and 800 degrees C had be reduced by half. Samples heated at 150 to 800 degrees C induced higher hydroxyproline increases than the non-heated sample. The fibrogenic activity of the dust heated at 1200 degrees C was very similar to the fibrogenic activity of the non-heated dust.

Air Pollutants↗
PubMed1985

[Evaluation of exposure of workers to asbestos dust in asbestos-processing plants].

Working environments have been tested in plants producing asbestos products, asbestos-cement products, textile asbestos products, asbestos-caoutchouc plates, asbestos boards and asbestos frictional materials for automotive industry, Measurements of total dust concentrations and concentrations of asbestos fibres 5 micron long supported workers' exposure investigations. Basing on literature data on the working environment at the Mining Metallurgical Plant in Szklary, the health risk for workers producing nickel from ores containing asbestos mixtures has been analysed. The asbestos-exposure in asbestos-processing plants has been found to be still considerable despite modernization of the plants. Particularly dangerous to health have been regarded the conditions at asbestos spinning-mills and the Mining-Metallurgical Plant at Szklary, where even average asbestos concentrations considerably exceed the threshold limit values.

Air Pollutants, Occupational↗
PubMed1985

[Principles of preventing the adverse health effects of occupational exposure to asbestos].

In view of biological effects of asbestos and hygienic evaluation of working conditions in the plants processing and applying asbestos, the authors promote preventive measures aimed at the protection of asbestos-exposed populations health. Apart from recommendations to reduce occupational exposure by technological means, the authors define medical contraindications to work, frequency and range of preventive examinations, as well as the need to monitor working environment, verify hygienic standards and introduce regulations limiting the admissible duration of work in exposure.

Air Pollutants, Occupational↗
PubMed1984

The effect of asbestos-cement, cement and asbestos dusts on the lungs of rats.

Experimental coniosis was induced by intratracheal administration to rats of 25 mg or 50 mg of Portland cement, asbestos-cement, as well as chrysotile and crocidolite asbestos. The rats were sacrificed 90, 165 and 180 days after dust administration. The weight of wet lungs and hydroxyproline content in lungs were determined. Statistically significant lower values of fibrogenic effects indices following cement dust administration, as compared to those indices for the other dusts, were found. On the other hand, no significant differences were found between fibrogenic effects indices for asbestos-cement containing approx. 13% of asbestos and pure asbestos dusts (chrysotile or crocidolite). Furthermore, it seems that the duration of dust action is more important than the dust dose in the development of fibrogenic asbestosis.

Animals↗
PubMed1983

[Dust and occupational diseases in brickyards].

Air dustiness and mineralogical composition of dust in 9 building ceramics plants producing red brick were tested. Also analysed were occupational diseases diagnosed in Poland during 1979-1980 in workers of this industry. Concentrations of total dust and respirable fraction at all workstations exceeded the present mandatory allowable values for dusts containing free crystalline silica. By X-ray diffraction, alpha-quartz and illite were found in raw materials (clays) and intermediate products (green brick). In burnt brick alpha-quartz and mullite were found. The content of free crystalline silica was: in clay--over 30%, in total dust--5.8-18.4%, in respirable fraction 3.7-6.1%. Analysis of occupational diseases diagnosed in Poland during 1979-1980 revealed not a single case of pneumoconiosis or any dust--induced respiratory tract disease in those producing red brick. Instead, two pneumoconiosis cases were found among workers of the plant producing thermallite firebrick of biologically aggressive siliceous earth from Piotrowice--as one of its component. Most frequently, workers of the building ceramics plant were afflicted with occupational dermatoses, mostly this relates to bricklayers exposed to cement mortar. Two cases of occupational dermatosis were those of workers exposed to ash.

Air Pollutants, Occupational↗
PubMed1983

[Incidence of pneumoconiosis and the fibrogenic properties of dust occurring during the production of thermallite bricks].

Notifications of occupational diseases among building ceramics industry workers were analysed. During 1976-1980 six cases of pneumoconiosis among those workers were diagnosed. All those cases referred to workers of two divisions dealing with transport and preparation of raw materials for the production of thermallite brick of a mixture of clay from Jarosław, siliceous earth from Piotrowice and sawdust. Experiments on animals confirmed a very high biological aggressiveness of unheated siliceous earth and weak fibrogenic activity of clay dusts and dusts emitting from the burned thermallite brick. Diffractometric tests of the dusts indicated that the high biological aggressiveness of siliceous earth was due to alpha-crystoballite of low crystallinity. Under effect of high temperature (during brick burning) crystoballite of siliceous earth is subject to great changes (the degree of crystallinity gets increased), which results in its decreased fibrogenic properties. The experiments on animals confirmed a weak biological aggressiveness of the dust from burnt thermallite brick and considerably decreased aggressiveness of siliceous earth heated at 1200 degrees C for 4 hours, as compared to unheated siliceous earth. The weak fibrogenic activity of the dust of clay containing approx. 15% of alpha-quartz may be due to kaolinite and illite in this dust.

Animals↗