Response to oyster mushroom (Pleurotus ostreatus) extract by sensitized and nonsensitized guinea pig trachea.

Occupational exposure to oyster mushroom (Pleurotus ostreatus) has been associated with obstructive lung disease. Previously, we studied an extract of oyster mushroom (OME) and determined that it causes dose-dependent contractions of nonsensitized guinea pig trachea (GPT). We extend these studies to the investigation of sensitized tissue. In the present study 24 animals were sensitized using ovalbumin (OA) and subsequently challenged with an aerosol of 2.5% OA. A control group of 12 nonsensitized GPs was also studied. Tracheas were removed and were divided into rings in which the epithelium was retained (EP+) or removed (EP-). Dose-related contractions of sensitized and nonsensitized GPTs were elicited with OME. In nonsensitized animals the EP+ GPTs demonstrated a significantly greater response to OME (100-1000 µl) than did the EP- GPTs (p < 0.01). By contrast, in sensitized GPTs with and without epithelium there was no difference to challenge with OME. Finally, sensitized GPTs with and without epithelium and nonsensitized GPTs with epithelium responded similarly to challenge with OME. These findings suggest that in nonsensitized animals there is an enhancement of contractile response to OME which is in part mediated by the GPT epithelium. In sensitized animals with or without epithelium, the level of bronchoconstrictor response is similar to that of the nonsensitized animals with epithelium, suggesting an enhanced constrictor response independent of epithelium in the sensitized animals.

Pharmacological study of oyster mushroom (Pleurotus ostreatus) extract on isolated guinea pig trachea smooth muscle.

Mushroom farm workers suffer from respiratory symptoms during the farming of mushrooms. The objective of this study was to analyze the effects of oyster mushroom (Pleurotus ostreatus) extract (OME) on isolated guinea pig tracheal smooth muscle in vitro. Isolated guinea pig tracheal tissue from 27 nonsensitized guinea pigs were studied. The OME was obtained from indoor mushroom growing fields and prepared as a 1:10 w/v aqueous solution. Dose-related contractions of nonsensitized guinea pig trachea were demonstrated using these extracts. The OME contained significant quantities of bacterial components (eg., endotoxin: 43,072.92 EU/mg). Parallel, pharmacological studies were performed by pre-treating the tissues with mediator-modifying agents including atropine, indomethacin, pyrilamine, BPB, acivicin, NDGA, captopril, TMB8 and capsaicin. Atropine consistently and strikingly reduced the contractile effects of this extract. These observations suggest an interaction of the OME with parasympathetic nerves or more directly with muscarinic receptors. Pretreatment with TMB8 (inhibitor of intracellular calcium mobilization) also significantly blocked the constrictor effect of OME, indicating a role of calcium mobilization in the constricting effect of OME. Inhibition of contraction by blocking of other mediators was less effective and varied depending on the drug. We conclude that OME causes a dose-related airway smooth muscle constriction by nonimmunological mechanisms involving a variety of airway mediators and possibly cholinergic receptors. This effect is not dependent on pre-sensitization of the guinea pigs.

Gender related differences of low level exposure to occupational irritants--a three-year follow-up of chemical industry workers.

The authors followed changes in the ventilatory function in a group of 102 chemical workers over a three year period to evaluate gender related differences on respiratory effects of low concentrations of occupational irritants. Measurements were performed annually and the results of ventilatory test were compared to predicted normal values. Lung function was measured by recording maximum expiratory flow-volume (MEFV) curves. Baseline data show ventilatory function impairments of the obstructive-restrictive type, as measured by the Tiffeneau index and FEV1. After one and two years of exposure, impairment in flow rates at low lung volumes became prominent. Analysis of lung function in three years of the study suggests obstructive impairments mostly in the larger airways accompanied by a restrictive component. The ventilatory flow at low lung volumes was characterized by obstruction, but not by restrictive findings. Women appear to be more sensitive than men to the irritant effects of these exposures as measured by flow rates at low lung volumes--the smaller airways (FEF50% = 82.7 +/- 23.6 in women and FEF50% = 92.1 +/- 32.1 in men; p = 0.017), while men experienced greater changes than women to irritant effects on their ventilatory capacity--the large airways (FVC = 99.6 +/- 10.6 in men and FVC = 106.74 +/- 9.8 in women; p = 0.001). The additive effect of smoking to environmental irritation is demonstrated by the proportionately lower lung capacity in smokers. Overall, the effect of these pollutants in women is more synergistic than additive.

Respiratory findings in farmworkers.

This investigation was designed to study respiratory problems in farmworkers. To better define the consequences of this work environment on respiratory health, 814 farmworkers (738 male and 76 female) were studied. The mean age of the men in this study was 38 years, and the mean duration of their employment was 15 years. For women, the mean age was 44 years and the mean duration of their employment was 10 years. Of the men, 56.5% were regular smokers, and 23.7% of the women were regular smokers. A group of 635 control workers without significant exposure to air pollutants were matched by sex, age, employment, and smoking habit. The prevalence of chronic symptoms among male farmworkers was greater (P < 0.01) than among male control subjects for chronic cough (24.8% vs 11.4%), chronic phlegm (22.8% vs 9.1%), and chronic bronchitis (20.1% vs 7.4%). Among women farmworkers, a significant difference was noted with controls for chest tightness (farmworkers, 21.1%; control subjects, 0%; P < 0.001). There was a high prevalence of acute symptoms among male and female farmworkers. In particular, farmworkers complained of more frequent cough, eye irritation, dyspnea, and throat irritation than did control subjects. For respiratory symptoms in male and female farmworkers, odds ratios were generally significant for smoking, age, and duration of employment. Ventilatory capacity tests were significantly reduced for farmworkers compared with predicted values. Regression analysis of ventilatory capacity tests in male farmworkers as a percentage of predicted values demonstrated significant coefficients for employment and smoking. Our data suggest that farmworkers are exposed to noxious agents that cause respiratory symptoms and ventilatory capacity impairment.

Occupational airway diseases.

In this review we describe characteristics of occupational airway diseases, as well as physical and chemical characteristics of agents inducing airway disease. Occupational airway diseases include industrial bronchitis, reactive airway dysfunction syndrome, bronchiolitis obliterans, and occupational asthma. High- and low-molecular weight substances associated with occupational airway disease are listed. The importance of host factors is stressed. Diagnostic approaches, particularly indicators for specific challenge testing with occupational materials, are described. Preventive and control measures are presented.

Respiratory function in active firefighters.

BACKGROUND: Exposure to environmental pollution during firefighting may results in the development of respiratory disorders in firefighters. METHODS: The health effects of firefighting on respiratory function was investigated in a group of 128 active firefighters by recording respiratory symptoms and measuring lung function. In addition, 88 control workers, not exposed to known pollutants were studied for the prevalence of acute and chronic respiratory symptoms. RESULTS: Significantly higher prevalences of dyspnea, nasal catarrh, sinusitis, and hoarseness were recorded in firefighters compared to control workers (P < 0.01). One subject developed asthma symptoms following two intense firefighting episodes. A high prevalence of acute symptoms experienced during and after fire extinguishing was also documented among these firefighters. Eye and throat irritation as well as headache were prominent. A logistic regression analysis of chronic respiratory symptoms demonstrated that odds ratios were significant for both duration of work exposure and for smoking. Lung function testing demonstrated a decrease in FEF75 in relation to predicted suggesting obstructive changes in the smaller airways. A regression analysis of ventilatory capacity tests indicated a positive relationship of forced vital capacity with length of employment, 1 s forced expiratory volume as well as FEF50 were related to smoking, and FEF75 was related to both smoking and length of employment. CONCLUSIONS: Our data suggest that firefighters are at risk for developing acute and chronic respiratory symptoms as well as obstructive airway changes.

Pharmacologic properties of brewery dust extracts in vitro.

STUDY OBJECTIVES: To study the effects of extracts of brewery dust on isolated guinea pig tracheal smooth muscle in vitro. DESIGN: Parallel pharmacologic intervention on guinea pig tracheal rings that were obtained from the same animal. SETTING: Mount Sinai School of Medicine, Department of Pulmonary Medicine. MATERIAL: The isolated guinea pig tracheal tissue of 18 guinea pigs. INTERVENTIONS: Pretreatment of guinea pig rings by mediator-modifying agents before challenge with the brewery dust extracts. MEASUREMENTS AND RESULTS: The effect of brewery dust extracts on isolated guinea pig tracheal smooth muscle was studied using water-soluble extracts of dust obtained from brewery materials, including hops, barley, and brewery yeast. Dust extracts were prepared as a 1:10 (wt/vol) aqueous solution. Dose-related contractions of nonsensitized guinea pig tracheas were demonstrated using these extracts. The dust extracts contained significant quantities of bacterial components (eg, endotoxin and n-formyl-methionyl-leucyl-phenylalanine), but these agents were not thought to contribute directly to the constrictor effect of the dusts. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with the following drugs known to modulate smooth muscle contraction: atropine; indomethacin; pyrilamine; LY171883; nordihydroguaiaretic acid; captopril; thiorphan; verapamil; and TMB8. The constrictor effects of the dust extracts were inhibited by a wide variety of agents, the patterns of which depended on the dust extract. Atropine consistently and strikingly reduced the contractile effects of these extracts. These observations may suggest an interaction of the extracts with parasympathetic nerves or, more directly, with muscarinic receptors. The inhibition of contraction by the blocking of other mediators was less effective and varied with the dust extract. CONCLUSIONS: We suggest that brewery dust extracts cause a dose-related airway smooth muscle constriction by nonimmunologic mechanisms involving a variety of airway mediators and, possibly, cholinergic receptors. This effect is not dependent on presensitization of the guinea pigs.

Respiratory findings in livestock farmworkers.

In this cross-sectional study, the prevalence of acute and chronic respiratory symptoms and lung function were investigated in 236 (169 male and 67 female) livestock farmworkers raising domestic animals, including cattle and horses. The prevalence of acute and chronic respiratory symptoms was recorded by administering a modified version of the British Medical Research Council questionnaire on respiratory symptoms. Lung function was measured by recording the maximum expiratory flow-volume curves from which the forced vital capacity, the one-second forced expiratory volume, and the maximum expiratory flow rates at 50% and the last 25% were measured. There was a significantly higher prevalence of almost all chronic respiratory symptoms in farmers compared with controls: highest among men for chronic cough (27.2%) and highest among women for dyspnea (28.3%). Typical symptoms of occupational asthma were diagnosed in 3.6% of the male and 1.5% of the female livestock farmers. A logistic regression analysis performed on chronic respiratory symptoms of livestock workers indicate significant effects of smoking (P < 0.001) on all symptoms except occupational asthma. A large number of male and female livestock farmworkers complained of acute work-related symptoms: highest for dry cough (52.2%) and shortness of breath (44.9%). Lung function data among these workers demonstrated a trend toward lower lung function in general. Multivariate analysis of lung function parameters indicate significant effects of length of employment and smoking in male and length of employment in female livestock farmworkers. The data suggest that employment in livestock farming may be associated in a dose-dependent manner with the development of acute and chronic respiratory symptoms and lung function changes.

[Occupational exposure to harmful materials in artistic activities]. / Profesionalne stetnosti u djelatnosti likovnih umjetnika.

Artists' activities such as sculptures, paintings, graphic designs, photography, restoration, glassblowing, glass cutting and ceramics are described. The hazards the artists are exposed to during their professional activities with potential dangerous effects on their health are listed. Diseases which can develop as a consequence of exposure to specific noxious agents in such in environment are described. Preventive measures (personal, technical and medical) which should be applied in order to prevent the development of diseases related to these specific working conditions are stressed.

[Evaluation of work capacity and/or disability in patients with overuse injury syndromes of the locomotor system]. / Ocjena radne sposobnosti i/ili invalidnosti u bolesnika sa sindromima prenaprezanja sustava za kretanje.

Clinical picture and subject's occupation are the main points of reference in the evaluation of work capacity in subjects with overuse syndrome. Particular attention is paid to the degree and the location of pain, as well as functional limitations with respect to demands of the workplace. If the diagnosis is right and therapy and rehabilitation intensive, overuse syndrome usually does not entail long sick leaves. Exceptions are the athletes and certain jobs which require longer periods of rehabilitation. Furthermore, untimely diagnosis and inadequate treatment may extend the period of incapacity. If the therapy and medical rehabilitation cannot completely remedy the functional deficit in performing the regular job, application of pension policy regulations may be necessary. This applies to the immediate danger of disability with the possibility to change the job for a more adequate one, as well as to the disability due to occupational or general incapacity to work. If the health condition predisposes younger persons to disability, they may exercise their right to professional rehabilitation. This review gives a list of occupational diseases and causes which may be applied to the disability generated by the overuse syndrome.

Respiratory findings in chemical workers exposed to low concentrations of organic and inorganic air pollutants.

BACKGROUND: Occupational exposure to respiratory irritants may effect respiratory function in workers exposed to ambient air pollutants in the workplace. METHODS: We studied 567 male and 135 female workers employed in two chemical plants in Zagreb, Croatia. Measurements of the ambient concentrations of air pollutants were performed. The mean age of the men was 37 years and mean duration of employment was 12 years; a majority of these workers were smokers. The mean age of the women was 37 years with a mean duration of employment of 14 years; only one-third of the women smoked. An unexposed group of 340 male and 110 female unexposed workers was also studied. Acute and chronic work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. RESULTS: There were higher prevalences for all chronic respiratory symptoms in exposed than in unexposed workers particularly among women, a majority of which were nonsmokers. Occupational asthma was recorded in three (0. 5%) of the men and in two (1.5%) of the women workers. Logistic regression analysis indicated that the presence of chronic respiratory symptoms among exposed workers was primarily associated with the amount of smoking. Additionally, there were high prevalences of acute symptoms during the work shift. Among the chemical workers these were greatest for eye irritation (male: 43. 9%; female: 51.9%), dryness of the throat (male: 43.4%; female: 57. 0%) and irritation of the throat (male: 37.4%; female: 56.6%). Ventilatory capacity data among the chemical workers demonstrated that most of the measured tests, particularly the FVC and FEV1 were significantly decreased compared to predicted (P < 0.01 or P < 0. 05)). In particular nonsmoking women exhibited abnormal lung function. The effect of smoking among exposed workers was demonstrated on all ventilatory capacity tests by regression analysis for all measured respiratory parameters. Both length of exposure and age were correlated with lung function loss for FVC. Measured pollutant levels were for the most part within acceptable standard limits. CONCLUSIONS: Our data suggest that in this population of chemical workers exposed to low levels of pollutants respiratory symptoms were primarily associated with smoking. Environmental effects, possibly due to an interaction of pollutants were also suggested.

[Specificity of diagnostic procedures in occupational diseases]. / Specificnosti dijagnostickih postupaka kod profesionalnih bolesti.

Characteristics and specificities of diagnostic procedures as a basis of diagnosis of occupational diseases are explained. The aforementioned include working history, clinical, laboratory and functional tests and evaluation of working environment. Examples of practical application of such procedures are listed.

Respiratory findings in mail carriers.

The results of the recording of respiratory symptoms and the measurement of lung function in 136 male postal workers employed as mail carriers were studied. In addition, the prevalence of chronic respiratory symptoms in 87 male nonexposed control workers was also examined. There was a significantly higher prevalence of chronic bronchitis (25.0%) and sinusitis (38.9%) in mail carriers than in control workers (13.8%; P < 0.05 and 2.3%; P < 0.01). A logistic regression analysis performed on the results of the study of chronic respiratory symptoms of mail carriers indicated a significant (P < 0.001) effect of smoking in this cohort, with the exception of occupational asthma. Mail carriers who smoked had a significantly higher prevalence of chronic cough (45.3%), chronic phlegm (39.1%), chronic bronchitis (39.1%) and sinusitis (53.1%) than mail carriers who were nonsmokers (18.1%; 12.5%; 12.5% and 26.4% respectively.) (P < 0.01). A high prevalence of acute symptoms developing during the work-shift was recorded, in both smokers and nonsmokers, being highest for upper airway symptoms, headache (50.0%), nasal catarrh (42.6%), and eye irritation (57.4%). The results of tests for average measured ventilatory capacity (as a percentage of predicted capacity) were significantly lower than expected, particularly for maximum flow rates at the last 25% of the vital capacity (FEF25), in both smokers (68.5%) and in nonsmokers (74.2%). A multivariate analysis of lung function parameters indicated a significant effect of employment conditions. The only major identifiable occupational exposure of mail carriers was to ambient air pollution for an average of 6 h per day as well as to adverse meteorological conditions. The measured ambient concentrations of major outdoor pollutants, primarily total suspended particulates, sulfur dioxide (SO2) and black smoke exceeded considerably the recommended Croatian maximum air quality standards over the past 10 years. Our study of mail carriers demonstrated that these workers were subject to respiratory symptoms associated with their smoking habits. Lung function findings suggested that occupational exposures, possibly to atmospheric pollution in combination with adverse meteorological conditions, may have led to lung function impairment in these workers.

Respiratory function in female workers occupationally exposed to organic dusts in food processing industries.

Respiratory consequences of work in food processing industry were studied in 764 female workers exposed to organic dusts associated with the processing of green and roasted coffee, tea, spices, dried fruits, cocoa and flour. A group of 387 female workers not exposed to respiratory irritants served as controls for the prevalence of acute (during work shift) and chronic respiratory symptoms. A greater prevalence of all acute and chronic respiratory symptoms was consistently found among exposed workers than among control workers. The highest prevalence of chronic respiratory symptoms was recorded for chronic cough (40%), followed by acute symptoms of dry cough (58.7%). The difference in the prevalence of chronic respiratory symptoms between the exposed and control workers was in general significant (p < 0.01 or p < 0.05). Mean acute reductions of lung function over the work shift were recorded in all of the studied groups; the mean across-shift decrease as a percentage of preshift values was particularly marked in FEF25 (-26.7%), FEF50 (-21.6%), followed by FEV1 (-9.9%) and FVC (-3.7%). The preshift (baseline) values of ventilatory capacity were decreased in comparison to the predicted ones, and were lowest for FEF50 and FEF25. This finding indicated an effect of organic dust on small airways. Our analysis suggested that both dust exposure and smoking history contributed independently to these respiratory findings. Disodium cromoglycate (DSCG) significantly diminished across-shift reductions for FEF50 and FEF25 in a subgroup of the examined workers. Our data suggested the female workers employed in food processing industry to be at risk of developing both acute and chronic respiratory symptoms as well as ventilatory capacity impairment as the result of occupational exposures.

[Occurrence of nonspecific symptoms of irritation in workers exposed to latex]. / Ucestalost nespecificnih iritacijskih simptoma u radnica izlozenih lateksu.

The study included 17 female workers employed in latex glove rubber manufacturing plants. The mean age was 42 years and the mean duration of employment 19 years. Subjects were predominantly nonsmokers. A control group of 17 nonexposed workers was also studied. Chronic respiratory symptoms and diseases as well as acute work-related symptoms were recorded for these workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves on which forced vital capacity (FVC), one second forced expiratory volume (FEV1) and maximum expiratory flow at 50% and the last 25% of the vital capacity (FEF50, FEF25) were read. Skin prick tests were performed with three types of latex (original material-latex 1, extract from gloves-latex 2, and extract of latex company Epypharm-latex 3). The prevalence of chronic respiratory symptoms was greater among latex workers (varying from 5.9% for occupational asthma to 58.8% for dyspnea) than among control workers (0%). There was a high prevalence of acute work-related symptoms, particularly for eye irritation (76.5%), dryness of the nose (70.6%), throat burning (70.6%), dryness of the throat (64.7%) and cough (58.8%). Measured ventilatory capacity data in latex workers were significantly lower in comparison to control, particularly for FEF25 (75.1 +/- 19.5%). Among latex gloves making workers one had positive skin reaction to latex 3 along with the symptoms of occupational asthma. Our data indicate that employment in latex making gloves may be associated with the development of occupational asthma, in addition to frequent nonspecific respiratory findings.

[Occupational medicine worldwide and in Croatia]. / Medicina rada u svijetu i u Hrvatskoj.

The development of occupational medicine, its complexity and international position as well as the actual and anticipated tasks connected with modernisation of industry, workers' health protection and humanization of work is presented. Education in the field of occupational medicine is also evaluated. Eighteen countries: ten in Europe, United States of America, Canada, Brasil and Chile from the area of South America, Israel, Japan, China and Singapore in Asia are included in the review. At the end, the development of occupational health services in Croatia, its present organisation, legislation, education and training, future needs and goals are shortly discussed.

Pharmacologic effects of cocoa and rye flour extracts on isolated guinea pig trachea.

Confectionery workers are exposed to a wide variety of organic dusts and aerosols. Previous studies with workers in a confectionery plant working with cocoa and rye flour indicate that these workers are at risk of developing adverse respiratory symptoms and lung function impairment. The effects of cocoa and rye flour extract on isolated guinea pig tracheal smooth muscle were studied using water-soluble extracts from cocoa and rye flour obtained from the studied confectionery plant. Dose-related contractions of nonsensitized guinea pig tracheal rings were demonstrated using both cocoa and rye flour extracts. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with drugs known to modulate smooth muscle contraction: atropine, indomethacin, pyrilamine, nordihydroguaiaretic acid (NDGA), acivicin, bromophenacyl bromide (BPB), 3,4,5-trimethoxybenzoate 8-(N,N-diethylamino)octyl ester (TMB8), captopril, and capsaicin. Constrictor effects of the dust extracts were inhibited by these agents, the pattern of which depended on the dust extract. Atropine consistently and significantly reduced the contractile effects of both extracts. These observations suggest a release of parasympathetic mediators by these extracts or more directly an interaction with muscarinic receptors. In addition, the constrictor effect of cocoa and rye flour extracts was significantly, but only partially, reduced by indomethacin, pyrilamine, BPB, and TMB8. Acivicin also partially decreased the constrictor effect of cocoa extract. Pretreatment of tracheal tissue with capsaicin also decreased the constrictor effects of high concentrations of cocoa and rye flour extracts. Data suggest that cocoa and rye flour extracts cause a dose-related constriction of airway smooth muscle by non immunological mechanisms involving cholinergic pathways and airway mediators such as histamine and the products of the arachadonic acid cascade. This effect is not dependent on the presensitization of guinea pigs.

Respiratory and immunological findings in brewery workers.

BACKGROUND: Occupational exposure of brewery workers to organic dusts such as hops, barley, and brewery yeast has the potential to change respiratory function and immunological status. METHODS: Ninety-seven male workers employed in a brewery plant were studied. The mean age of the workers in this plant was 40 years, the mean duration of their employment was 16 years. In addition, a group of 76 unexposed workers was studied as a control. Respiratory symptoms were recorded. Lung function was measured by recording maximum expiratory flow-volume (MEFV) curves. Immunological testing was performed on all brewery workers and some control volunteers using skin prick testing with hops, barley, and yeast antigens as well as other nonoccupational allergens, and by determining total serum IgE levels. RESULTS: There was a significantly higher prevalence of most of the chronic respiratory symptoms in brewery workers compared to controls (P < 0.01). Occupational asthma, however, was recorded in only 2 (2.1%) of the brewery workers. Logistic regression analysis showed that smoking was the major studied factor responsible for the high prevalence of chronic respiratory symptoms in workers. A large number of brewery workers complained of acute symptoms that developed during the work shift. Lung function tests were decreased compared to predicted. Multivariate analysis of these respiratory function parameters suggested the importance of workplace exposure in explaining lung function abnormalities. Significantly higher prevalences of positive skin prick tests were recorded in 37 brewery workers for molds, hops, and barley than in controls. Increased serum levels of total IgE were documented in 34/97 (45.1%) brewery workers and in 1/76 (2.7%) of the control workers (P < 0.01). However, workers with positive skin prick tests had prevalences of chronic respiratory symptoms and lung function changes similar to those of workers with negative skin prick tests. CONCLUSION: Our data suggest that both smoking and dust exposure in the brewery industry may be responsible for the development of respiratory impairment and immunological reactions.

Respiratory function and immunological status in paper-recycling workers.

The respiratory function and immunological status of workers employed in the paper recycling industry were studied. The mean age of the 101 studied workers was 41 years, and the mean duration of their exposure was 17 years. A group of 87 unexposed workers of similar age, duration of employment, and smoking history was studied for the prevalence of chronic respiratory symptoms. Lung function in the paper workers was measured by recording maximum expiratory flow volume (MEFV) curves and recording forced vital capacity (FVC), 1-second forced expiratory volume (FEV1), and maximum expiratory flow rates at 50% and the last 25% of the FVC (FEF50, FEF25). Immunological studies were performed in all 101 paper workers and in 37 control workers (volunteers). These included skin-prick tests with paper-dust extracts and other nonoccupational allergens, as well as the measurement of total serum immunoglobulin E. Significantly higher prevalences of all chronic respiratory symptoms were found in paper compared with control workers (P < 0.01). The highest prevalences were found for chronic cough (36.6%), chronic phlegm (34.7%), chronic bronchitis (33.7%), sinusitis (31.7%), and dyspnea (18.8%). Occupational asthma was diagnosed in four (4.0%) of the paper workers. A logistic regression analysis performed on chronic respiratory symptoms of paper workers indicated significant effects of smoking and exposure, with the smoking effect being the most important. Multivariate analysis of lung-function parameters indicate significant effects of exposure. For paper workers, the measured FEF50 and FEF25 were significantly decreased, compared with predicted values, suggesting obstructive changes located primarily in smaller airways. Among 101 tested paper workers, 16 (15.8%) had positive skin-prick tests to at least one of the paper extracts; none of the control workers reacted to these extracts. Increased serum IgE levels were found in 21% of the paper workers and in 5% of control workers (P < 0.05). Paper workers with positive skin-prick tests to any of the paper and/or other tested extracts had higher prevalences of chronic respiratory symptoms and lower measured lung-function tests compared with predicted than did those with negative skin-prick tests, but the differences were not statistically significant. The measured concentrations of total and respirable dust in this industry were higher than those recommended by Croatian standards. Our study suggests that work in the paper-recycling industry is associated with respiratory impairment and that sensitive workers employed in this industry may be at particular risk of developing chronic respiratory abnormalities.

Sensitization to storage mites in urban working environment.

This paper presents an analysis of a medical history questionnaire, skin prick test and specific IgE to storage mites Lepidoglyphus destructor and Tyrophagus putrescentiae performed on 26 male paper mill workers and 36 postmen. Positive prick test were considered urticas with the mean diameter of 3 mm or over. Increased specific IgE were considered values of over 0.35 kU/L. Paper mill workers manifested a significantly higher frequency of positive test results, increased specific IgE and positive prick test, to L. destructor and T. putrescentiae than did the postmen. Paper mill workers with increased specific IgE manifested significantly greater mean skin reactivity to T. putrescentiae than to L. destructor. Respiratory symptoms were found in 40% of paper mill workers with positive test results to L. destructor, and in 53.8% with positive test results to T. putrescentiae. All postmen with positive test results to L. destructor and 83.3% with positive test results to T. putrescentiae had respiratory symptoms. The study results indicate that it is necessary to monitor sensitization to mites and to establish methods for identification and quantification of mites in the working and general environment.