Endotoxin in the occupational environment of bakers: method of detection.

The present study was conducted in a large mechanical city bakery. The AS-50 aspirators equipped with cellulose membrane filters were used for dust sampling. Airborne microbial content was assessed by means of sedimentation and aspiration using an Andersen sampler on Petri plates containing McConkey's medium. The following Gram-negative rods were detected in the bakery atmosphere: Erwinia herbicola, Acinetobacter Lwoffi and Klebsiella oxytoca, in concentrations ranging from 1.4 10(4) to 3.5 10(5) colony forming units per cubic meter (cfu/m3). Endotoxin concentration in flour dust sampled in selected work areas of the bakery ranged from 6.7 micrograms of endotoxin per gram of dust (micrograms/g) to 20.3 micrograms/g. Endotoxin level in the air was 0.04-0.05 micrograms of endotoxin per cubic meter (micrograms/m3). The results of our show that aspiration sampling is necessary for evaluation of airborne bacterial content and demonstrate the efficacy of the Limulus test of varying sensitivity to assay endotoxin level in the airborne dust. The advantage of this method is the possibility of assessing endotoxin in crude dust extracts.

[Correlations between selected indicators of asbestos dust pollution of the work environment]. / Zaleznosci pomiedzy wybranymi wskaznikami oceny zanieczyszczen pylem azbestu srodowiska pracy.

Occupational exposure to asbestos dust induces many diseases, of which the most dangerous are: asbestosis, pulmonary cancer and pleural endothelioma. Exposure to asbestos dust is evaluated by: total gravimetric concentration of dust, gravimetric concentration of respirable fraction or numerical concentration of asbestos fibres of over 5 microns. The research has been aimed to establish whether or not there are correlations between the mentioned indices of asbestos dust exposure. The concentrations have been measured at various workstations in the plants producing textile asbestos products, frictional and asbestos--cement products. The gravimetric concentrations have been determined using the filtration--gravimetric method with cyclonic pre-selector and without selector. The numerical concentration of fibres has been determined by a microscopic phase--contrast method. The statistical analysis of the obtained results showed no correlation between particular indices, or--weak correlations (r = 0.004-0.76). No correlation has been found between total gravimetric concentration and numerical concentration of asbestos fibres. The ratio between those concentrations was 0.094-4.69, therefore both those concentrations should be included while evaluating the working conditions of those exposed to asbestos dusts.

[Evaluation of the work environment in factories producing artificial mineral fibers (MMMF)]. / Ocena srodowiska pracy w zakladach produkujacych sztuczne wlókna mineralne (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.

[Evaluation of exposure of workers to asbestos dust in asbestos-processing plants]. / Ocena narazenia pracowników na pyl azbestu w zakladach przerabiajacych azbest.

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.

[Microscopic quality control--numeric representation of asbestos fiber concentration in environmental air of the workplace]. / Kontrola jakosci mikroskopowo--liczbowych oznaczen steenia respirabilnych wlókien azbestu w powietrzu srodowiska pracy.

The study aimed at assessing the reliability of determinations of respirable asbestos fibre concentration which were performed by selected laboratories of the Work Hygiene Departments of the Regional Sanitary Epidemiological Stations (RSES). Two rounds of microscopic specimen exchanges were organized, the specimens containing from 20 to 700 asbestos fibres per 1 mm2. The results of specimen density determinations performed by RSES analysts were compared with reference determinations (i.e. average density determinations performed by 7 workers of the Institute of Occupational Medicine, Lodz, checked by two international tests). During the first exchange, the RSES determinations were found to be significantly lower than the reference determinations. At the second exchange, they exceeded the reference values. The poor precision of determining asbestos fibre concentration by the majority of the RSES analysts makes it necessary to provide additional training for that group, apart from that a survey of the quality of RSES laboratory equipment should be carried out and a system of internal quality control for the RSES laboratories should be developed and implemented.

[Air concentration of asbestos fibers at work sites]. / Oznaczanie stezenia wlókien azbestu w powietrzu stanowisk pracy.

The paper presents a method for measuring the concentration of asbestos fibres at workplaces. This method consists in sampling the dusted air onto membrane filters, making the filters transparent and counting asbestos fibres under an optical microscope with a positive phase contrast. Errors in counting asbestos fibres, sampling and precision of the method were discussed (total error of the method). Measurements of the concentration of asbestos fibres in the air at workplaces were made at plants producing asbestos textile products, seal plates, packings and frictional goods. 0.1 fibre/cm3 was the lowest concentration (sensitiveness of the method).

[Occupational exposure to asbestos-containing dust at the plants manufacturing and using asbestos products during the years 1986-1989]. / Ekspozycja zawodowa na pyly zawierajace azbest w zakladach produkujacych i stosujacych wyroby azbestowe w latach 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).

[International control of the quality of microscopic-numerical analysis of the levels of man-made mineral fibers (MMMF) in the air of the work area]. / Miedzynarodowa kontrola jakosci mikroskopowo-liczbowych analiz oznaczania stezenia sztucznych wlókien mineralnych (MMMF) w powietrzu srodowiska pracy.

In the years 1986-1990 the Institute of Occupational Medicine in Lodz (Department of Aerosols) participated in seven exchanges of preparations within the WHO/Euro MMMF Reference Scheme programme. The number of persons analysing the preparations increased from three, during the first exchange, to seven in the sixth. Markings in the 1st and 3rd exchange constituted two thirds of the reference markings. In the 2nd, 5th and 7th exchange the markings were similar, and in the 6th exchange they were lower than in the reference markings. According to the accepted system, the markings of the standardized density in four exchanges (2nd, 5th, 6th and 7th) were determined as class I (0.70-1.40), and in the remaining exchanges (1st, 3rd and 4th) of class II (0.50-2.00).

[Evaluation of the biological effect of polishing powders]. / Ocena biologicznego dzialania proszku polerskiego.

Polishing powders are applied as abrasives at the treatment of various metal surfaces prior to their electroplating. The polishing powder is composed of: technical paraffin, dibutyl phthalate, technical borax, ammonium sulfate, aloxite or corundum and, as a carrier, sawdust of decidous or coniferous trees. Evaluated were: exposure to the polishing powder dust of workers operating polishing machines, as well as fibrogenic properties of the powder in an experiment on animals polishing machines, and irritating and allergic effects upon human skin (determination of irritation halftime, rubbing, damping and epidermal tests). The results demonstrated that the mean geometric concentrations of the dust ranged from 3.1 to 6.4 mg/m3 of air, whereas the dust respirable fraction constituted approx. 20% of the total dust concentration. The content of free crystalline silica in the dust did not surpans 2%. In the experiment on animals the dust exhibited cytolytic effects and induced reactive lesions in form of granulomas. The content of hydroxyproline in rats' lungs when affected by the polishing powder approximated the values obtained with quartz of weak fibrogenic properties. Basing on dermatological studies, the irritating effects of the polishing powder were defined as medium, whereas the allergic effects as weak.

[Fly ash and its biological effects. 3. Exposure to dust of workers in the energy-generating industry (power plants and thermoelectric power stations)]. / Popioly lotne i ich dzialanie biologiczne. 3. Narazenie na pyl pracowników zatrudnionych w zakladach energetyki (elektrowniach i elektrocieplowniach).

An evaluation of exposure to dust of workers employed at typical work-stands in power industry plants was made. Mean concentrations of respirable dust determined at 14 different work-posts range from 0.45 to 8.95 mg/m3, and of total dust from 1.55 to 85.0 mg/m3. Mean content of free crystalline silica in dust samples is less than 10%. At the work-stands where ash dust was encountered, the presence of respirable fibres at concentration below 0.2 fibre/cm3 was observed. In all ash samples alpha-quartz and mullite were found: in some of them also kaolinite and orthoclase were traced. Only at five out of all 14 work-stands examined mean concentration of respirable dust was lower than the hygienic standard value.

[Asbestos substitutes and their biological action. I. Types, use, exposure and MPEL]. / Zamienniki azbestu i ich dzialanie biologiczne. 1. Rodzaje, zastosowanie, narazenie i skutki biologiczne, NDS.

Referring to literature, the authors present problems of exposure to asbestos, its production and MACs in Poland. In our country artificial mineral fibres are produced in seven plants employing about 2000 workers. These plants produce basalt wool, sag wool and glass fibres used in industrial and building insulating materials and in cement and mortar additives and as a free insulating material. Mean concentrations of total dust at the work-posts measured in 1986-1989 ranged between 1.06 mg/m3 and 3.10 mg/m3. Concentrations of respirable fibres ranged from 0.041 fibre/cm3 to 0.173 fibre/cm3. In Poland, the MAC for mineral fibres for total dust amounts to 4 mg/m3 and for respirable mineral fibres to 2 fibres/cm3.

[Dust and occupational diseases in brickyards]. / Pyl i choroby zawodowe w cegielniach.

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.

[Assessment of exposure to bioaerosols in workplace ambient air during municipal waste collection and disposal]. / Ocena narazenia pracowników na bioaerozole, wystepujace w powietrzu na stanowiskach pracy w czasie zbierania i zagospodarowywania odpadów komunalnych.

The assessment of the exposure to bioaerosols among workers engaged in the collection and disposal of municipal waste is presented. The workers were divided into the following groups, depending on the job performed: waste collectors (loaders, drivers), composting plant workers (heavy equipment operators, waste site workers), sorters (heavy equipment operators, waste sorters) and landfill site workers (heavy equipment operators, weighers). Air samples were also collected on the city streets and in flats. They were reference points to the results obtained. Air samples were collected at the breathing zone. The concentrations of dust, viable microorganisms (mesophilic and thermophilic bacteria, and fungi), endotoxins and the total number of microbiol cells were determined. The highest, individual exposure to dust was found in composting plant workers and waste collectors. The values exceeded considerably maximum allowable concentrations (by ten times at composting plant). The mean values for the above listed groups also exceeded the concentration of 4 mg/m3. Dust concentrations at other workposts were substantially lower. The concentrations in the city streets and in flats maintained at the level of 0.1 mg/m3. Endotoxin concentration at a protecting upper airway inflammation level (10 ng/m3) was exceeded in the majority (above 50%) of samples. That is why the average concentration in individual groups was also higher than 10 ng/m3. Street and flat samples included endotoxins at the level of 1 ng/m3. Taking as a criterion the obligatory total dust and endotoxin MAC value of 10 ng/m3 for assessing work hygiene conditions, it should be stated that waste collectors and composting plant workers were employed in conditions of poor hygiene.