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PubMed1996

Equivalent diameter of standard quartz dust used as a test aerosol for the dust respirator.

In the standard of the approval test for dust respirator certification, test aerosols are defined as air containing quartz particles of 2 microns or smaller1. However, it is well-known that the filtration efficiency of air filters depends on the size of the test aerosol particles. Alternative test aerosols containing submicron size particles will be studied for use in future approval test of dust respirators. Before searching for alternatives, characterization of currently-used quartz dust, e.g. information about size and electrostatic charge of the aerosol particles, should be determined. The currently-used approval test measures filtration efficiencies with a light scattering photometer. The photometer gives overall aerosol concentration, while Aerodynamic Particle Sizer (APS-33B, TSI Inc., St. Paul, U.S.A.) is able to give the number concentration for each particle size based on the aerodynamic diameter ranging from 0.9 to 2.0 microns. In this study, equivalent diameter was defined as the diameter at which penetration has the same value when measured by APS-33B and by light scattering photometer. The equivalent diameter for the ten filter samples for dust respirator was around 1 microns, irrespective of neutralization of the test aerosol.

Aerosols↗
PubMed2000

Effects of exposure to flax dust in Polish farmers: work-related symptoms and immunologic response to microbial antigens associated with dust.

Medical examinations were performed in a group of 51 Polish farmers heavily exposed to flax dust during harvesting and scutching (threshing) and in a group of 50 healthy urban dwellers not exposed to organic dusts (controls). The examinations included: interview concerning the occurrence of respiratory disorders and work-related symptoms, physical examination, X-ray examination of chest, lung function tests, oxymetric examinations, determination of the concentration of cytokines (IL-1alpha IL-6, TNFalpha) in blood serum and allergological tests with microbial antigens associated with organic dust, comprising: skin prick test with 4 antigens, agar-gel precipitation test with 12 antigens and test for specific inhibition of leukocyte migration with 4 antigens. As many as 32 farmers (62.7%) reported the occurrence of work-related symptoms during harvesting, transporting and scutching of flax. The most common complaint was general weakness reported by 15 farmers (29.4%), followed by headache reported by 14 (27.5%), blocking of the nose - by 11 (21.6%), dry cough, shivering, and eyes itching - each by 10 (19.8%), chest tightness and hoarseness - each by 9 (17.6%). No control subjects reported these work-related symptoms. The mean spirometric values in the examined group of farmers were within a normal range and did not show a significant post-shift decline. In contrast, a significant post-shift decline of oxymetric values was found among flax farmers. The farmers showed a frequency of the positive early skin reactions to environmental allergens in the range of 0-19.6%, a frequency of positive precipitin reactions in a range of 0-56.9%, and frequency of positive reactions of leukocyte migration inhibition in a range of 7.8-21.6%. The members of the control group responded to the majority of allergens with a significantly lower frequency of positive results compared to the farmers. Elevated concentrations of IL-1alpha and IL-6, but not TNFalpha, were found in blood sera of flax farmers. In conclusion, farmers engaged in harvesting and scutching of flax represent a group of elevated professional risk because of high incidence of work-related symptoms and high frequency of allergic reactions to bacteria and fungi associated with organic dust.

Adult↗
PubMed1992

[Expression of TNF-alpha in alveolar macrophages after stimulation with quartz dust, welding fume dust and asbestos fibers].

Alveolar macrophages have a potential for expressing and excreting many factors that are immunologically active and active on cytokines (monokines and lymphokines) and are thus indirectly involved in the genesis of pulmonary fibroses. One of these factors is the tumour necrosis factor alpha (TNF alpha). In the study presented here, the expression of TNF alpha-mRNA was investigated in macrophages stimulated in vitro with quartz dust, dust from cinders of welding furnaces, and asbestos, using non-radioactive in situ hybridization. There was a marked dependence of the expression of this cytokine on both time and stimulation. Macrophages stimulated by quartz dust showed the highest rate of expression compared with controls and other related stimuli. In addition, all stimuli yielded an expression that was elevated for a short period only and reached its peak after four hours. The results permit the conclusion that various professionally inhaled dusts possess different risk potentials in respect of lung damage mediated by macrophages and do not behave uniformly.

Animals↗
PubMed1979

[Immunological investigations of house-dust and house-dust mites. Part III. A simplified basophil degranulation test. Preliminary communication (author's transl)].

The basophil degranulation test (BDT) after Shelley has been simplified and tried on patients allergic to house-dust or to house-dust mites. All 20 patients reacted to the mite extracts and 19 out of 20 to the house dust extracts. Out of 20 control persons 17 had negative results to the mite extract and 16 to the house-dust extract. The advantages of this new simplified method are discussed.

Basophils↗
PubMed2006

[Effect of PM2.5 collected during the dust and non-dust periods on the viability and gap junctional intercellular communication in human lung fibroblasts].

OBJECTIVE: To investigate the effects of PM2.5 collected during the dust and non-dust periods on the viability and gap junctional intercellular communication (GJIC) in human lung fibroblasts. METHODS: Human lung fibroblasts were treated with PM2.5 suspension and its organic and inorganic extracts at various concentrations for 24 h. The cellular viability was measured with MTT methods, and the GJIC between human lung fibroblasts was detected by the scrape loading dye transfer assay. RESULTS: PM2.5 suspension from both sources and the inorganic extracts of dust PM2.5 significantly decreased the viability of human lung fibroblast in a dose-dependent manner. Compared with other preparations, the dust PM2.5 suspension had the highest effect. Gap junctional intercellular communication between human lung fibroblasts was significantly inhibited by the different composition of PM2.5 from both sources in a dose-dependent manner. The inhibitory effects on GJIC were in the order of organic extract of PM2.5 > suspension > inorganic extract. CONCLUSION: Composition and source of PM2.5 are important factors which influnce the toxic effects on cells. The composition of PM2.5 from both sources can inhibit GJIC, suggesting decreasing GJIC may be related to the biological mechanisms of toxicity caused by PM2.5.

Air Pollutants↗
PubMed2006

[Evaluation of the prevalence of house dust mites in house dust sent to the Adnan Menderes University Medical Faculty Parasitology Laboratory].

House dust is composed of remnants and particles of many kinds of animate and inanimate materials. It has been reported that the most common allergens in house dust are mites that cause allergic rhinitis, asthma, atopic dermatitis, and seasonal keratoconjunctivitis. The aim of this study was to determine the prevalence of house dust mites in dust specimens sent to our laboratory from November 2002-May 2004. Specimens were evaluated using the flotation concentration method in the first, fourth and 24th hours. Out of 88 specimens, mites were detected in 20 (22.72%). In addition Enterobius vermicularis eggs were found in two specimens.

Allergens↗
PubMed1977

[Specific surface factor of dust particles and preliminary selection of silica dusts].

The results of particles analysis of three kinds of silica dust by means of miscroscopy and sedimentation in Andreasen's pipette served as a base for the determination of factor phi specific for particle surface. This factor is expressed as a ratio of the mean projected diameter (dp) to the aerodynamic diameter (d). The formula of the factor is: (formula: see text). The value of factor phi for tested silica dusts ranges from 2.0 to 2.6 (mean value--2.3), while the variability coefficient is 13.5%. Taking into account the value of factor phi determined by experiment and the value of dispersion of silica dust particles, the expected permeability of the selector (elutriator) and the deposition of dust in lungs were calculated.

Dust↗
PubMed1986

Biomonitoring of industrial dusts on animals. I. Bioaccumulation of dust components.

The bioaccumulation of industrial dust components in laboratory animals exposed by inhalation was studied under environmental conditions. Three types of industrial emissions were investigated: magnesite emissions, wastes from nickel refinery and cement emissions, respectively. The findings revealed that the chemical components of the industrial dust particles inhaled by animals are accumulated not only in the lungs, but also in the other organs, bone and hair of the exposed animals. In addition, the dust components were found in the organs of the F1 generation as well. This suggests a new aspect for the assessment of the biohazard of industrial dust particles in the environment.

Air Pollutants↗
PubMed1980

[Considerations in diagnosis and therapy of house dust and house dust mites allergy (author's transl)].

In all patients with perennial complaints an allergy should be considered. This predominantly monosymptomatic disease is most often caused by house dust mites (Dermpteron. and Derm. farinae) and less often by animal dander, occupational dust and molds. The diagnosis and treatment of allergies includes anamnesis, skin tests with industrially produced allergenes, skin tests with house dust and occupational dust, the avoidance of the allergenes and the hyposensitization.

Child↗
PubMed1995

[The calculation and regulation of dust exposure doses to decrease the level of occupational diseases of dust etiology].

One of the real ways to reduce occupational diseases caused by dust is to cut the duration of contact with dust. The studies helped to suggest a method calculating occupational risk correlated to dust content of the air. The authors evaluated the duration of contact with dust so as to reduce occupational risk to the minimum. Those measures appeared to lower but not eliminate the occupational risk.

Discriminant Analysis↗
PubMed1995

[Dust exposure, dust-induced lung diseases and respiratory protective measures in agriculture].

Epidemiologic studies indicate a high prevalence of respiratory diseases among the farming population. Many of these diseases are responsible for disability and death and there is a considerable impact on the economy and health cost expenditure. Respirable organic dust plays a major pathogenetic role. Part I of this review discusses the diseases and syndromes caused by organic dust: organic dust toxic syndrome; chronic bronchitis and chronic obstructive pulmonary disease; asthma; and hypersensitivity pneumonitis. Part II describes preventive measures for dust control. Besides technical aspects in the process of agriculture production, special emphasis is placed on personal protective equipment systems (face-masks and air-purifying respirators). Applications, advantages and disadvantages of these systems are discussed and critically compared.

Agricultural Workers' Diseases↗
PubMed1994

[The evaluation of hyposensitization with house dust in patients with nasal allergy to house dust-mite].

We evaluated the clinical and pathophysiological efficacy of hyposensitization with house dust extracts to perennial nasal allergy. Fifty-one patients with allergic perennial rhinitis completed 5 months to 15 years with a mean of 2.4 years course of hyposensitization treatment with house dust extracts, and analyzed clinical symptoms, nasal provocation testing, nasal hypersensitivity to histamine, mast cells and eosinophils in nasal scraping, specific IgG and IgG4 antibody in serum, and blood eosinophils and basophils in relation to therapeutic duration. The improvement in nasal symptoms was found in 74.1% in adults and 66.7% in child and the continuation of hyposensitization with house dust extracts for a half to one year showed significant improvement of clinical symptoms. In objective examination, nasal provocation testing, nasal hypersensitivity to histamine, the number of mast cells and eosinophils in nasal scraping, and blood basophils showed significant improvement at 6 to 12 months the same as clinical symptoms. These findings suggest that the continuation of hyposensitization with house dust extracts is recommendable as a basic treatment against perennial nasal allergy.

Adolescent↗
PubMed1994

[Effect of a mite-killing agent on house dust and on symptoms of house dust allergy].

UNLABELLED: The efficacy of acaricid benzyl-benzoate (Acarosan) has been followed in an open study for one year in patients with house dust mite allergy; the clinical signs and the mite allergen level have been considered. METHODS: the furniture (beds, upholstered pieces, carpets) of 17 house dust mite allergic patients suffering from bronchial asthma and/or allergic rhinitis has been investigated. The mite content of the dust gained from the furniture has been determined with the help of the semiquantitative Acarex test. This test has been done before the mite elimination and 3, 6, 9 and 12 months after it. The registered clinical signs of the patients: symptoms, drug consumption, expiratory peak flow values have been measured twice a day. RESULTS: 9/17 beds have become free from mites, 6/17 beds have had less mites than before, 1/17 no change, 1/17 augmentation of mite content. The proportion of days free from complaints has been 26.8% at the beginning of the trial and 47.1% after 12 months, the drug consumption has diminished meanwhile. At the beginning of the trial 6 children had pathologic lability index based on peak-flow measurements, they improved significantly. The information about the mite content of the furniture gives help for the elimination measures. The chemical mite elimination reduces the mite content of the flat and results in clinical improvement of house dust mite allergic patients.

Acari↗
PubMed1998

Effects of exposure to grain dust in Polish farmers: work-related symptoms and immunologic response to microbial antigens associated with dust.

Medical examinations were performed in a group of 76 Polish farmers heavily exposed to grain dust during harvesting and threshing, and in a group of 63 healthy urban dwellers not exposed to organic dusts (controls). The examinations included: interview concerning the occurrence of respiratory disorders and work-related symptoms, physical examination, lung function tests, and allergological tests comprising skin prick test with 4 microbial antigens associated with grain dust and agar-gel precipitation test with 12 microbial antigens. As many as 34 farmers (44.7%) reported the occurrence of work-related symptoms during harvesting and threshing. The most common was dry cough reported by 20 individuals (26.3%). Dyspnoea was reported by 15 farmers (19.7%), tiredness by 12 (15.7%), chest tightness by 8 (10.5%), plugging of nose and hoarseness by 5 each (6. 5%). No control subjects reported these work-related symptoms. The mean spirometric values in the examined group of farmers were within the normal range, but a significant post-shift decrease of these values was observed after work with grain. The farmers showed a frequency of the positive early skin reactions to environmental allergens in the range of 10.8 - 45.5%, and a frequency of positive precipitin reactions in range of 3.9 - 40.8%. The control group responded to the majority of allergens with a significantly lower frequency of positive results compared to the farmers. The obtained results showed a high response of grain farmers to inhalant microbial allergens and indicate a potential risk of occupational respiratory diseases (such as allergic alveolitis, asthma, Organic Dust Toxic Syndrome) among this population

Adult↗
PubMed1992

Diseases associated with exposure to plant dusts: focus on cotton dust.

Research during recent years has made clear that pulmonary disease and certain general symptoms caused by organic dusts are far more common than previously suspected. To the traditional environments of cotton dust and moldy hay has been added a series of environments, such as swine confinement buildings, sewage treatment stations and industrial fermentation plants. It has been suggested that, rather than linking clinical disease with a specific environment (farmer's lung, byssinosis, etc), symptoms should be related to the relevant pulmonary cellular reactions, particularly inflammation. In so doing, a more homogenous picture of the various clinical entities has emerged. It is now understood that symptoms once considered to be unique to one particular environment, such as chest tightness in cotton mills, are also present in other organic dust environments. New models for organic dust-induced disease have been established using the criteria developed for disease among workers in cotton mills and swine confinements buildings. This has led to uniform methods for diagnosis, description of symptomatology and understanding of pathogenesis. Employing this experience on an international basis, provides an important background for dealing with new problems in this important area of occupational health and is a prerequisite for the establishment of treatment and prevention programs.

Byssinosis↗
PubMed2004

Dust-lower-hybrid drift instabilities with dust charge fluctuations in an inhomogeneous dusty magnetoplasma.

Effects of a uniform magnetic field, the plasma inhomogeneity, and dust charge fluctuations on low-frequency dust-lower-hybrid drift waves have been investigated. Charging currents of electrons and ions to a spherical dust grain in a nonuniform magnetized dusty plasma have been calculated to study the charge fluctuation induced damping or growth of low-frequency drift waves. It is found that for strongly magnetized electrons and ions, the charge fluctuation damping is reduced significantly from that of an unmagnetized plasma. For sufficiently hot electrons, the drift wave exhibits instability in the absence of dust charge fluctuation damping.

Journal Article↗
PubMed1988

Generation of free oxygen radicals from human polymorphonuclear granulocytes by cytokines from human mononuclear cells, treated with quartz dust DQ12 or coal mine dust TF-1--new aspects in pathogenesis of pneumoconiosis.

We report about the release of a soluble mediator(s) from cultured human monocytes/macrophages after exposure to quartz dust DQ12 or coal mine dust TF-1. This mediator(s) activates isolated human polymorphonuclear granulocytes (PMN) to generation of free oxygen radicals. The strong and long-lasting production of reactive oxygen species (ROS), especially of superoxide anion, was measured as lucigenin dependent chemiluminescence (CL). Studies of mediator exposed PMN with the NBT-test (nitroblue-tetrazolium test) also demonstrated the strong activation of PMN. Electromicroscopical studies of mediator exposed PMN showed strong chemotactic changes in a time dependent manner and suggested the release of lysosomal products. According to these properties we called the mediator(s) "granulocyte activating mediator(s)" (GRAM). Biochemical characterisation indicated a protein nature of GRAM. High pressure liquid chromatography (HPLC) gel-filtration suggested that two molecules or two fragments of one molecule with a m.w. of about 20 kda and just below 10 kda resp. were responsible for the observed effects. PMN are potent inflammatory cells, which are known to immigrate in the lung tissue, especially in the early phases of silicosis. ROS released by activated PMN can act tissue destroying, mutagenic and are probably involved in collagene synthesis by regulation of activity of prolylhydroxylase. Mediator induced release of ROS seems to be an important event in development of lung fibrosis and presents a new mechanism of quartz dust and coal mine dust fibrogenicity.

Biological Factors↗
PubMed1997

Respiratory impairments due to dust exposure: a comparative study among workers exposed to silica, asbestos, and coalmine dust.

We conducted a comparative study of pulmonary dysfunction among workers who were exposed to silica, asbestos, or coalmine dust. The results showed that all three groups of dust-exposed workers, even those without radiographic signs of pneumoconiosis, had decreased spirometric parameters and diffusing capacity (DLco) in both nonsmokers and smokers. Pulmonary function was further decreased when pneumoconioses were present in the three groups. In accord with increasing radiographic categories, pulmonary function in the workers with either silicosis or asbestosis was even lower, whereas in those with coal workers' pneumoconiosis (CWP), it changed relatively little. Workers with mild to moderate (radiographic category I-II) silicosis or asbestosis showed similarly decreased DLco, but those with silicosis showed lower FEV1/FVC than those with abestosis. The workers with CWP also showed a lower FEV1/FVC than those with asbestosis. The major impairment patterns for silica workers, asbestos workers, and coal miners were mixed, restrictive and mixed, and obstructive, respectively. Smoking obviously increased the prevalence of obstruction for all the groups. We conclude from the present study that all the three dusts cause functional abnormalities that precede radiographic changes of pneumoconiosis. We should pay more attention to respiratory impairment in the initial stage of silicosis and CWP.

Adult↗