Asthma-like symptoms, atopy, and bronchial responsiveness in furniture workers

Wood Dust Exposure Levels and Respiratory Symptoms 6 Years Apart: An Observational Intervention Study Within the Danish Furniture Industry

OBJECTIVES

Occupational exposure to wood dust can cause respiratory diseases, but few studies have evaluated the impact of declining exposure on health outcome. This study aimed to investigate whether a decline in wood dust exposure between two cross sectional studies performed in 1997-1998 and 2003-2004 was related to the prevalences of respiratory symptoms among woodworkers in a well-defined geographical area.

METHODS

Two thousand and thirty-two woodworkers from 54 plants in study 1 and 1889 woodworkers from 52 plants in study 2 returned a questionnaire on respiratory diseases and symptoms, employment and smoking habits. Current individual wood dust exposure level was assessed from 2 study specific job exposure matrix's based on task, factory size and personal passive dust measurements (2217 in study 1 and 1355 in study 2).

RESULTS

The median (range) of inhalable dust was 1.0 mg/m3 (0.2-9.8), 0.6 mg/m3 (0.1-4.6) in study 1 and study 2, respectively. In study 2, the prevalence's of self-reported asthma was higher and the prevalence's of respiratory symptoms were lower compared to study 1. In adjusted logistic regression analyses using GEE methodology to account for clustering, dust exposure level could explain the differences in prevalence of coughing, chronic bronchitis and nasal symptoms between study 1 and study 2, while no effect was found for asthma.

CONCLUSIONS

A 40% decline in wood dust exposure in a 6 year period may serve as an explanation for the decline in most respiratory symptoms, but do not seems to impact the prevalence of self-reported asthma.

Specific work activities and exposure to respiratory hazards - predictors of lung function impairment among crop farmers

OBJECTIVE: The objective of the study was to evaluate the specific work activities and occupational exposure to respiratory hazards as predictors of chronic respiratory symptoms development, lung function decline, and respiratory health impairment among crop farmers. METHODS: A cross-sectional survey was performed, including 87 crop farmers (mean age: 53.4 ± 7.8 years; and mean exposure duration: 22.9 ± 7.8 years) and 80 office workers as a control group (mean age: 52.7 ± 8.2 years) matched for age, smoking habits, and socioeconomic status. Subjects were evaluated by a questionnaire on respiratory symptoms in the past 12 months and spirometry testing. RESULTS: Crop farmers had a significantly higher prevalence of cough (41.4), phlegm (28.7%), and dyspnea (21.8%), than controls (p < 0.05). All mean baseline spirometric parameters were lower in crop farmers, but statistical significance was confirmed only for MEF25, MEF50, and MEF75 (p = 0.003, p = 0.000, and p = 0.001, respectively). Most of the respiratory symptoms were significantly associated with common work activities of crop farmers and all-day exposure to certain respiratory hazards. Age, exposure duration, and their combined effect with smoking habit had a significant effect on forced expiratory volume in one second FEV1 and FEV1/forced vital capacity. CONCLUSION: The results confirm that occupational exposure among crop farmers is associated with higher prevalence of respiratory symptoms and lung function decline and, together with specific workflow activities, may not only be a predictors of respiratory health impairment, but also a key tool in the creation of preventive strategies.

Asthma and rhinitis in Greek furniture workers

Objective: The detection of asthma and rhinitis in furniture workers exposed to chemicals in the area of Thessaloniki Greece and the determination of the most useful tests for diagnosing the above occupational diseases.Methods: Eighty-three workers (76 men), 35 exposed to chemicals (CW), 23 to wood dust (WW), and 25 office workers (OW), serving as controls, filled in a specialized European Community Respiratory Health Survey (ECRHS) questionnaire for asthma and were submitted to clinical evaluation, spirometry, bronchodilation test, PEF computer algorithm OASYS-2, FeNO, skin prick tests (SPTs), rhinomanometry and methacholine inhalation challenge. Working conditions and protective measurements were also recorded. According to the results of all conducted tests, each subject was distributed to a subgroup: (a) normal, (b) asthma, (c) rhinitis, (d) asthma and rhinitis. Comparisons were performed among work groups.Results: The presence of asthma and/or rhinitis was higher among CW and WW compared to OW (p = 0.004). Significant differences among groups were observed in the questions «better weekend» (p < 0.034) and "improvement on vacation» (p < 0.000), in OASYS-2 Score (p < 0.000), in ABC Score (p < 0.000), and in methacholine score (p < 0.022). Rhinomanometry, FeNO, spirometry, and spirometry after bronchodilation had no significant differences among groups. Working conditions, ventilation system, work practice, use and type of mask revealed no significant differences.Conclusion: Asthma and rhinitis are significantly common among CW. Protective measurements used were not adequate to prevent asthma and or work related rhinitis. Early diagnosis might contribute to disease prevention and control.

Asthma in furniture and wood processing workers: a systematic review

BACKGROUND

Wood dust is a common cause of occupational asthma. There is potential for high exposure to wood dust during furniture and wood manufacturing processes.

AIMS

To evaluate the evidence for non-neoplastic respiratory ill health associated with work in the furniture and wood manufacturing sector.

METHODS

A systematic review was performed according to PRISMA guidelines. Articles were graded using SIGN (Scottish Intercollegiate Guideline Network) and MERGE (Methods for Evaluating Research Guidelines and Evidence) criteria, with data grouped by study outcome.

RESULTS

Initial searches identified 1328 references, from which 55 articles were included in the review. Fourteen studies were graded A using MERGE or >2++ using SIGN. All but one paper describing airway symptoms reported an increased risk in higher wood dust exposed workers in comparison to lower or non-exposed groups. Five studies reporting asthma examined dose response; three found a positive effect. The relative risk for asthma in exposed workers in the single meta-analysis was 1.5 (95% CI 1.25-1.87). Two studies reported more obstructive lung function (forced expiratory volume in 1 s [FEV1]/forced vital capacity < 0.7) in exposed populations. Excess longitudinal FEV1 decline was reported in female smokers with high wood dust exposures in one study population. Where measured, work-related respiratory symptoms did not clearly relate to specific wood immunoglobulin E positivity.

CONCLUSIONS

Work in this sector was associated with a significantly increased risk of respiratory symptoms and asthma. The evidence for wood dust exposure causing impaired lung function is less clearly established. Further study is required to better understand the prevalence, and causes, of respiratory problems within this sector.

Respiratory symptoms and pulmonary functions of workers employed in Turkish textile dyeing factories

Dyes are known to be a causative agent of occupational asthma in workers exposed to them. We have evaluated respiratory symptoms among textile workers. The study population comprised 106 exposed workers and a control (unexposed) group. Data were collected by a questionnaire. PFTs (Pulmonary Function Test) were performed. Among the exposed workers 36.8% defined phlegm. Respiratory symptoms were not significantly different between two groups. The employment duration of the exposed workers with phlegm was longer than those without phlegm (p = 0.027). The mean % predicted of FEF(25-75) of the exposed workers was found to be significantly lower than the control (unexposed) group (p = 0.01). Our study suggests that textile dyeing might cause respiratory symptoms in workers.

Effect of occupation and smoking on respiratory symptoms in working children

OBJECTIVES

To compare the respiratory symptoms and the lung function of children who work in different occupational groups.

METHODS

The study was performed among children attending vocational training centers. The participants were evaluated in six different occupation groups. Chronic cough, wheezing and shortness of breath were evaluated by questionnaire. The association of independent variables with the respiratory symptoms was investigated through both univariate and multivariate methods.

RESULTS

Among 642 children, 534 were males; the mean age was 17.7 +/- 1.0 years. Using an internal reference group, the odds ratios of chronic cough were significantly higher in the lathe (OR: 2.0, 95%CI: 1.07-3.74), coiffure (OR: 1.94. 95%CI: 1.01-3.70), and electricity-construction (OR: 2.63, 95%CI: 1.06-6.54) groups after adjustment for smoking, age, gender, and work characteristics. There were no significant differences in spirometric values between occupational groups in either smoking or non-smoking males. In non-smoking females, median values of FEV(1) (P: 0.046), PEF (P: 0.005) and FEF(25-75%) (P: 0.019) were lower in the textile compared to the coiffure group. There was no significant association between the total working time and spirometric values. There was no statistically significant relationship between the work-related factors and the smoking status.

CONCLUSIONS

The prevalence of chronic cough was higher in the lathe, coiffure, and electricity-construction groups and pulmonary function tests were lower in the non-smoking textile female group. Working children should be screened for respiratory symptoms and disease.

Five annual observations of respiratory findings in gun factory workers exposed to solvents

OBJECTIVE

We investigated whether long-term, low-level exposures to solvents had adverse longitudinal effects on pulmonary functions.

METHODS

The study was performed on 1091 workers 5 years ago and then on 697 workers 5 years later. Chronic respiratory symptoms were recorded using a questionnaire on respiratory symptoms.

RESULTS

The annual decrease in forced expiratory volume in 1 second in the workers exposed to solvents was not significantly different from that of the unexposed workers (69.7 +/- 89.9 vs 75.8 +/- 87.6 mL/yr, P = 0.5, respectively). In 453 workers who were exposed to solvents 5 years ago, the prevalence rate of asthma was 1.1%. Five years later, it was 3.6% in 193 workers from the same group. The difference was statistically significant (P = 0.03).

CONCLUSIONS

Longitudinally, the chronic exposure to low doses of solvents does not adversely affect the pulmonary functions, whereas it increases the asthma prevalence.

Occupational asthma in subjects occupationally exposed to herbal and fruit tea dust

We performed a cross-sectional study to detect occupational asthma (OA) in 63 subjects occupationally exposed to herbal and fruit tea dust and in 63 corresponding controls. The evaluation included a questionnaire, skin prick tests to workplace and common inhalant allergens, spirometry, and histamine challenge test. The evaluation of the work-relatedness of asthma in the exposed workers was based on serial peak expiratory flow rate (PEFR) measurements and bronchoprovocation tests. We found a higher prevalence of respiratory symptoms in the exposed workers, whereas spirometric parameters were significantly lower. The prevalence of sensitisation to allergens and of bronchial hyperresponsivenss (BHR) did not differ significantly between the groups. The prevalence of asthma was also similar in both groups (8.0 % vs. 6.4 %; P=0.540). Work-relatedness of symptoms was reported by all asthmatic tea workers and by no control with asthma. Significant work-related changes in PEFR diurnal variations and in non-specific BHR, suggesting allergic OA, were found in one tea worker with asthma (1.6 %). No specific workplace agent causing OA in the affected subject was identified. None of the tea workers with asthma met the criteria for medical case definition of the reactive airway dysfunction syndrome (RADS). Our data confirm workplace exposure to herbal and fruit tea dust as a risk factor for OA.

Respiratory symptoms, sensitization, and exposure response relationships in spray painters exposed to isocyanates

RATIONALE

Associations between oligomeric isocyanate exposure, sensitization, and respiratory disease have received little attention, despite the extensive use of isocyanate oligomers.

OBJECTIVES

To investigate exposure-response relationships of respiratory symptoms and sensitization in a large population occupationally exposed to isocyanate oligomers during spray painting.

METHODS

The prevalence of respiratory symptoms and sensitization was assessed in 581 workers in the spray-painting industry. Personal exposure was estimated by combining personal task-based inhalatory exposure measurements and time activity information. Specific IgE and IgG to hexamethylene diisocyanate (HDI) were assessed in serum by ImmunoCAP assay and enzyme immunoassays using vapor and liquid phase HDI-human serum albumin (HDI-HSA) and HSA conjugates prepared with oligomeric HDI.

MEASUREMENTS AND MAIN RESULTS

Respiratory symptoms were more prevalent in exposed workers than among comparison office workers. Log-linear exposure-response associations were found for asthmalike symptoms, chronic obstructive pulmonary disease-like symptoms, and work-related chest tightness (prevalence ratios for an interquartile range increase in exposure of 1.2, 1.3 and 2.0, respectively; P </= 0.05). The prevalence of specific IgE sensitization was low (up to 4.2% in spray painters). Nevertheless, IgE to N100 (oligomeric HDI)-HSA was associated with exposure and work-related chest tightness. The prevalence of specific IgG was higher (2-50.4%) and strongly associated with exposure.

CONCLUSIONS

The results provide evidence of exposure-response relationships for both work-related and non-work-related respiratory symptoms and specific sensitization in a population exposed to oligomers of HDI. Specific IgE was found in only a minority of symptomatic individuals. Specific IgG seems to be merely an indicator of exposure.

Indices of asthma among atopic and non-atopic woodworkers

AIMS

To investigate the relation between wood dust exposure and different indices of asthma among woodworkers and non-exposed subjects.

METHODS

A total of 302 woodworkers and 71 non-exposed subjects answered a respiratory health questionnaire, underwent a non-specific bronchial provocation test using the Yan method, and received a skin prick test with 12 common inhalant allergens. Subgroups performed repeated peak flow monitoring and underwent a reversibility test. A total of 347 dust measurements among 234 woodworkers were performed with passive dust monitors.

RESULTS

The overall geometric mean (geometric standard deviation) exposure to inhalable dust was 0.96 (2.02) mg/m3. There was a tendency to increased risk of asthma among atopic woodworkers compared to atopic non-exposed subjects, with ORs between 3.0 (0.8-11.9) (symptomatic BHR) and 1.3 (0.5-4.2) (work related symptoms). In woodworkers, asthma was associated with atopy, with ORs between 7.4 (2.8-19.7) (symptomatic BHR) and 4.2 (2.4-7.7) (asthma symptoms). Asthma was related to dust level, most pronounced for symptomatic BHR among atopics, with OR 22.9 (1.0-523.6) for the highest compared to the lowest dust level. For work related asthma symptoms the association with dust level was seen only for non-atopics.

CONCLUSIONS

Wood dust exposure was associated with asthma, despite a low dust level compared to other studies. Atopy was an important effect modifier in the association between asthma and wood dust exposure.

Interaction of atopy and smoking on respiratory effects of occupational dust exposure: a general population-based study

BACKGROUND

For individual exposures, effect modification by atopy or smoking has been reported on the occurrence of occupational airway disease. It is unclear if effect modification can be studied in a general population by an aggregated exposure measure. Assess relationship between airway obstruction and occupational exposure using a job-exposure-matrix (JEM) classifying jobs into 3 broad types of exposure, and test for effect modification by atopy, and smoking.

METHODS

Data from 1,906 subjects were analyzed, all participants of the European Community Respiratory Health Survey. Job titles were categorized by an a priori constructed job exposure matrix into three classes of exposure to respectively organic dust, mineral dust, and gases/ fumes. Relationships were assessed for 'current wheeze', bronchial hyperresponsiveness (BHR), 'current asthma' (wheeze+BHR), and 'chronic bronchitis' (morning phlegm or morning cough), and lung function.

RESULTS

Subjects with organic dust exposure in their work environment more frequently had 'current asthma' (OR 1.48, 95% C.I. 0.95;2.30), and a lower FEV1 (-59 mL, 95% C.I. -114;-4). The relationship was only present in asthmatic workers, and their risk was four-fold greater than in subjects with either atopy or exposure alone. Mineral dust exposure was associated with 'chronic bronchitis' (OR 2.22, 95% C.I. 1.16;4.23) and a lower FEV1/FVC ratio (-1.1%, 95% C.I. -1.8;-0.3). We observed an excess risk in smokers, greater than the separate effects of smoking or mineral dust exposure together.

CONCLUSION

Occupational exposure to organic dust is associated with an increased risk of asthma, particularly in atopics. Chronic bronchitis occurs more frequently among individuals exposed to mineral dust, and smoking doubles this risk.

Respiratory findings in gun factory workers exposed to solvents

OBJECTIVE

Gun factory workers are exposed to many solvents (toluene, acetone, butanol, xylene, benzene, trichloroethylene). We investigated whether chronic exposure to solvents had adverse effect on respiratory system.

MATERIAL AND METHODS

The workers were questionnaired by modified Medical Research Council's respiratory questionnaire before morning start shift. Then physical examination and measurement of pulmonary functions by portable dry rolling spirometer were performed. The study group consisted of 1091 gun factory workers. The workers were grouped according to their smoking habits (smokers, [exposed n: 353 vs. unexposed n: 339] and non-smokers [exposed n: 58 vs. unexposed n: 341]). Asthma-related symptoms were defined as either definite asthma, probable asthma, and possible asthma.

RESULTS

In non-smokers, the report of asthma-related symptoms was more prevalent in exposed workers than unexposed (39.7% vs. 21.7% OR 2.4[1.3-4.3], respectively P = 0.003). In smokers, the report of asthma-related symptoms was more common in exposed group than unexposed (50.7% vs. 42.5% OR 1.4[1.0-1.9], respectively P = 0.03). Logistic regression analysis showed that smoking (OR 2.8[2.0-3.8] P = 0.00001) and exposure to solvents (OR 1.4[1.1-1.9] P = 0.01) were independent risk factors for asthma-related symptoms, after adjusting for age. Logistic regression analysis identified that smoking (OR 3.3[2.3-4.6] P = 0.00001) was independent risk factors for chronic bronchitis. Multiple linear regression analysis of lung-function parameters (% forced expiratory volume (FEV1), FEV1/forced vital capacity, FEF(25-75)) indicated significant effects of smoking.

CONCLUSION

Present study indicated significant effects of smoking and exposure to solvents, with the smoking effect being the most important on asthma-related symptoms of gun factory workers.

Diisocyanate-exposed auto body shop workers: a one-year follow-up

BACKGROUND

Diisocyanates currently are the most commonly identified cause of occupational asthma in industrialized countries. Auto body shops, a common hexamethylene diisocyanate (HDI) exposure setting, are difficult to study due to their small size and episodic exposures.

OBJECTIVES

A 1-year follow-up was undertaken as an adjunct to the cross-sectional SPRAY study (Survey of Painters & Repairers of Auto bodies by Yale) to investigate the effects of HDI on auto body shop workers over time and whether or not the healthy worker effect may exist in this industry.

METHODS AND RESULTS

Forty-eight workers from seven shops were re-contacted. Thirty-four subjects who stayed at the same shop and 11 who left their original shop participated. No statistically significant changes in physiology, symptoms, and immunologic responses from baseline to follow-up were noted. However, significant differences between those who left the shops and those who stayed were noted. Those who left were younger, less experienced in the industry, and more likely to have a history of asthma (23 vs. 3%; P < 0.05), bronchial hyper-responsiveness (23 vs. 9%), HDI-specific IgG (64 vs. 29%; P < 0.05), and HDI-specific proliferation (S.I. 2.0 vs. 1.3; P < 0.05).

CONCLUSIONS

The differences in workers who stayed at their shop compared to those who left, combined with the low asthma prevalence and high job turnover rate, all suggest that a healthy worker effect may exist in the auto body industry, and may in part account for the low prevalence of asthma noted in SPRAY and other cross-sectional studies of diisocyante workers.

Diagnosis of flour-induced occupational asthma in a cross-sectional study

The diagnosis of occupational asthma is usually performed in epidemiology using a combination of symptoms and bronchial hyperresponsiveness, while in a clinical setting the 'gold standard' for the diagnosis of occupational asthma is the specific bronchial challenge test in the laboratory The aim of this study was to detect new cases of flour-induced occupational asthma (OA) in a group of workers exposed to grain and/or flour dust, by means of a step-by-step approach, as used in a clinical setting. In an epidemiological study, III millers and 186 bakers were examined by means of questionnaire, pulmonary function tests and skin-prick tests (SPT) to common allergens and to wheat flour dust extracts. From the whole sample, 82 subjects who showed asthma-like symptoms in the questionnaire and/or low forced expiratory volume in 1 sec (FEV1) were selected. Selected subjects underwent methacholine challenge test, and hyperreactive subjects underwent specific bronchial challenge with flour dust in the laboratory. Sixty-two of the selected subjects performed the methacholine challenge test, and 22 (33 8%) were hyperreactive (PD20 FEV1 <1 mg of methacholine). Fifteen of 22 hyperreactive subjects underwent specific bronchial challenge test (s BCT) with flour dust; a positive response was elicited in six subjects. These subjects can be diagnosed as having flour-induced occupational asthma. Atopy and skin sensitivity to flour was partially related to the response to flour bronchial challenge. Bronchial hyperreactivity can be observed in a small percentage of subjects with asthma-like symptoms and/or low FEV1, and a positive response to s BCTwas observed in a subgroup of hyperreactive subjects.Therefore, using these selection criteria, a diagnosis of flour-induced OA, as commonly performed in a clinical setting, can be performed in few previously undiagnosed subjects.This approach could be relevant for an early diagnosis ofoccupational asthma.

Respiratory symptoms and lung function among Danish woodworkers

A cross-sectional study including 54 furniture factories and three control factories was conducted to survey lung function and prevalence of respiratory symptoms among woodworkers. Spirometry was performed on 2423 persons. Questionnaires regarding respiratory symptoms and wood dust exposure were completed by 2033 woodworkers and 474 controls. Personal passive dust measurements were performed on 1579 persons. The arithmetic mean +/- SD for equivalent inhalable dust was relatively low (1.19 +/- 0.86 mg/m3). Woodworkers had increased frequency of coughing with negative interaction between dust exposure and smoking. A dose-response relationship was seen between dust exposure and asthma symptoms, and a positive interaction for asthma was seen between female gender and dust exposure. Increased frequency of wheezing and a cross-shift decrease in forced expiratory volume in 1 second among workers using pinewood was seen. In conclusion, wood dust exposure might cause respiratory symptoms, despite a relatively low exposure level.