The incidence of respiratory symptoms and diseases among pulp mill workers with peak exposures to ozone and other irritant gases

OBJECTIVES: Pulp mills in Sweden started to use ozone as a bleaching agent in the early 1990s. The goal of this study was to investigate whether the incidence of selected respiratory outcomes was associated with peak exposures to ozone or other irritant gases (ie, chlorine dioxide [ClO2] or sulfur dioxide [SO2]) used in these mills. METHODS: Bleachery workers (n = 245) from three pulp mills where ozone was used participated in surveys in the mid- to late-1990s. Comparison workers (n = 80) were from two adjacent paper mills. The person-time at risk was calculated for each participant, covering the period of employment when ozone was used. Data were collected by questionnaire, and a peak exposure was defined as a self-reported exposure to an irritant gas resulting in acute respiratory symptoms. The outcomes analyzed were self-reports of physician-diagnosed asthma, attacks of wheeze, and chronic bronchitis (ie, chronic cough with phlegm). Participants also reported when the peak exposures and outcomes occurred. RESULTS: Based on proportional hazards regression (controlling for gender, age, cigarette smoking, atopy, and peak irritant exposures that occurred before follow-up), workers who reported both ozone and ClO2/SO2 peak exposures had elevated hazard ratios (HRs) for all three outcomes. Those who reported only ozone peak exposures had elevated HRs of 6.5 (95% confidence interval [CI], 1.2 to 36.3) for asthma and 3.3 (95% CI, 1.1 to 10.2) for attacks of wheeze but no increase in risk for chronic bronchitis. Workers with only ClO2/SO2 peak exposures had elevated HRs for attacks of wheeze (HR, 7.5; 95% CI, 1.9 to 29.3) and chronic bronchitis (HR, 22.9; 95% CI, 4.5 to 118.2) but not for asthma. CONCLUSIONS: These findings suggest the need for additional efforts to prevent peak exposures in pulp-bleaching operations.     

Definitions and types of work-related asthma: a nosological approach.

The workplace can trigger or induce asthma and cause the onset of different types of work-related asthma. Analysis of previous definitions of occupational asthma (OA) led to the conclusion that evidence of a direct causal relationship between workplace exposure and the development of asthma remains the key element for defining OA. Based on clinical features and pathophysiological mechanisms, the following conditions should be distinguished in the spectrum of work-related asthma: 1) immunological OA characterised by a latency period necessary to acquire immunologically induced sensitisation; 2) nonimmunological OA characterised by the rapid onset of asthma following single or multiple exposures to high concentrations of irritant compounds; 3) work-related asthma defined by exacerbation of symptoms in workers with pre-existing or coincident asthma; and 4) variant syndromes including eosinophilic bronchitis, potroom asthma, and asthma-like disorders caused by organic dusts. The issues and controversies relating to this approach are critically reviewed in order to stimulate the consensus development of operational definitions of work-related asthma.     

Comparison of individuals with and without specific IgA antibodies to Chlamydia pneumoniae: respiratory morbidity and the metabolic syndrome

STUDY OBJECTIVES: To determine whether a correlation exists between markers for persistent Chlamydia pneumoniae infection, respiratory morbidity, and the metabolic syndrome. DESIGN: Case-control study. A group of individuals with serologic markers (specific IgA > or = 1/128) suggestive of persistent C pneumoniae infection were compared with a group of control subjects without IgA antibodies (< 1/32). SETTING: Apoteksg?rdens Health Care Center, Kopparberg, Sweden. PARTICIPANTS: One hundred case subjects (61 men and 39 women) and 100 control subjects matched for age and gender (mean age, 55 years). Measurements and results: Individuals completed a questionnaire on respiratory symptoms and smoking habits. Body mass index (BMI) was calculated, BP, and peak expiratory flow (PEF) were determined. Blood specimens were drawn for determination of high-sensitivity C-reactive protein (hsCRP), blood glucose level, serum lipids, and Chlamydia antibodies. No significant difference was found between case subjects and control subjects regarding myocardial infarctions, stroke, diabetes type II, BP, BMI, hsCRP, blood glucose levels, and serum lipids. Symptoms of both asthma and chronic bronchitis were more common in case subjects, as were symptoms of chronic upper respiratory tract infections (p < 0.005). Case subjects with asthma or chronic bronchitis had more chronic upper respiratory tract disorders (p < 0.05). Symptoms of chronic respiratory tract diseases increased parallel to increasing specific C pneumoniae IgA antibody titers (p < 0.0005). PEF percentage of the predictive value was inversely correlated (p < 0.0005) to IgA antibody titers. CONCLUSION: The data show that persistent increased levels of C pneumoniae IgA antibodies were associated with pronounced respiratory dysfunction. These data provide additional evidence suggesting that IgA antibodies may be a marker for persistent C pneumoniae infection.     

The effect of biomass fuel exposure on the prevalence of asthma in adults in India – review of current evidence

Introduction: The combustion of biomass fuels is a major source of respiratory disease among individuals in the developing world. Over two million people world-wide rely on biomass fuels to supply their household energy needs with an estimated 1.6 million deaths annually being attributable to biomass smoke exposure. As a developing country, India relies heavily on the use of solid fuels as a source of energy. These materials supply 75% of the country’s domestic energy need and are attributed as the cause of over 600?000 deaths annually. Diseases such as chronic bronchitis and acute lower respiratory tract infections are strongly correlated to biomass smoke exposure. While not as strongly correlated, accumulating evidence suggests that asthma prevalence may be related to solid fuel smoke. Methods: This review examines the current literature linking biomass smoke exposure to the reporting of asthma symptoms. A PubMed search was performed using key terms biomass, asthma, India and respiratory disease. Preference was given to recent articles that surveyed the adult population within India. Results: The reviewed articles showed an increased odds ratio for reporting a diagnosis of asthma or symptoms consistent with asthma following biomass smoke exposure. While the literature supports a strong association between household air pollution and the development of chronic bronchitis and acute lower respiratory tract infections in India, this review establishes a more firm relationship between reported asthma symptoms and biomass smoke exposure. Conclusion: The exposure to biomass fuel smoke results in respiratory diseases in developing countries. Among these diseases, asthma appears to be a preventable pulmonary pathology that is associated with household air pollution. Measures to reduce exposure may decrease the burden of disease which could help advance social and economic progress in these nations. Further research and out-reach efforts are needed to reduce the total burden of lung diseases, including asthma, across the developing world. This reduction could save millions of dollars annually and lower morbidity and mortality in the affected populations.     

Irritant-Induced Asthma in the Workplace

Irritant-induced asthma in the workplace has been the focus of several articles in the past few years, and reviewed here. A clinical case definition is most readily associated with a single acute/accidental exposure to a presumed high concentration of an agent or agents expected to be irritant to the airways, as was initially reported with the subgroup Reactive Airways Dysfunction Syndrome (RADS). When most but not all criteria for RADS are met, then a diagnosis of irritant-induced asthma may also be considered to be “more probable than not”. However, in addition, there is evolving understanding from epidemiological studies that chronic exposures may be associated with an increased risk of developing asthma. Despite this recognition, the mechanisms and clinical case definitions of work-related asthma that might be caused by chronic exposures to irritants (vs. new-onset asthma that begins coincidentally to work exposures), remain unclear at present.     

Ventilatory capacity, working capacity and exercise-induced bronchoconstriction in a population sample of subjects with bronchial asthma or chronic bronchitis.

We have studied a representative population sample comprising 185 persons, aged 35-54 years, having certain respiratory symptoms and considered to have chronic bronchitis and/or bronchial asthma. There were 86 with bronchial asthma (without chronic bronchitis), 69 with chronic bronchitis (without asthma) and 30 with both chronic bronchitis and bronchial asthma. Fifty-one of the 116 asthmatics had reaginic bronchial allergy. In the groups with chronic bronchitis or bronchial asthma, the mean ventilatory capacities were slightly below the normal, being 89 and 91%, respectively, of the predicted values for FEV1 and 85 and 87% of those for MVV40. In the group of persons with both diseases, the mean FEV1 was 77% and the mean MVV40 84% of that predicted. Of the 21 persons with a mean FEV1 below 70% of that predicted 10 had both asthma and bronchitis. Exercise-induced bronchoconstriction, defined as a 15% fall of PEF after exercise, occurred in 22 of the 116 asthmatics and in one of the 69 persons with chronic bronchitis without bronchial asthma. In the asthmatics there was a significant correlation between resting PEF or the difference in PEF before and after orciprenaline inhalation on the one hand, and exercise-induced bronchoconstriction on the other hand. This was taken as an indication of increased bronchial hyperreactivity.     

Occupational risk factors and asthma among health care professionals

RATIONALE: Recent U.S. data suggest an increased risk of work-related asthma among health care workers, yet only a few specific determinants have been elucidated. OBJECTIVES: To evaluate associations of asthma prevalence with occupational exposures in a cross-sectional survey of health care professionals. METHODS: A detailed questionnaire was mailed to a random sample (n=5,600) of all Texas physicians, nurses, respiratory therapists, and occupational therapists with active licenses in 2003. Information on asthma symptoms and nonoccupational asthma risk factors obtained from the questionnaire was linked to occupational exposures derived through an industry-specific job-exposure matrix. MEASUREMENTS: There were two a priori defined outcomes: (1) physician-diagnosed asthma with onset after entry into health care ("reported asthma") and (2) "bronchial hyperresponsiveness-related symptoms," defined through an 8-item symptom-based predictor. MAIN RESULTS: Overall response rate was 66%. The final study population consisted of 862 physicians, 941 nurses, 968 occupational therapists, and 879 respiratory therapists (n=3,650). Reported asthma was associated with medical instrument cleaning (odds ratio [OR], 2.22; 95% confidence interval [CI], 1.34-3.67), general cleaning (OR, 2.02; 95% CI, 1.20-3.40), use of powdered latex gloves between 1992 and 2000 (OR, 2.17; 95% CI, 1.27-3.73), and administration of aerosolized medications (OR, 1.72; 95% CI, 1.05-2.83). The risk associated with latex glove use was not apparent after 2000. Bronchial hyperresponsiveness-related symptoms were associated with general cleaning (OR, 1.63; 95% CI, 1.21-2.19), aerosolized medication administration (OR, 1.40; 95% CI, 1.06-1.84), use of adhesives on patients (OR, 1.65; 95% CI, 1.22-2.24), and exposure to a chemical spill (OR, 2.02; 95% CI, 1.28-3.21). CONCLUSIONS: The contribution of occupational exposures to asthma in health care professionals is not trivial, meriting both implementation of appropriate controls and further study.     

Asthma-like symptoms in wood product plant workers exposed to methylene diphenyl diisocyanate

BACKGROUND: Diisocyanates, a group of highly reactive chemicals, have frequently been associated with occupational asthma. We evaluated respiratory health in workers at a new wood products manufacturing plant that uses methylene diphenyl diisocyanate (MDI), and was designed and operated with a goal of minimizing worker exposures. METHODS: Health surveys using standardized respiratory questionnaires were done prior to the initial use of diisocyanates in the plant, and semiannually thereafter for a period of 2 years. Other testing included occupational and work practice histories, serial peak flow measurements, spirometry, methacholine challenge, and measurement of specific IgE antibodies to MDI-albumin conjugate. RESULTS: Of 214 plant employees who participated in at least one health survey, a follow-up survey was also available from 178 employees (83%). New-onset asthma-like symptoms (NAS) were reported by 15 of 56 workers (27%) in areas with the highest potential for exposures to liquid MDI monomer and prepolymer, vs 0 of 43 workers in the lowest potential exposure areas (p = 0.001). In the areas with high potential exposure, NAS developed in 47% of workers who had noted MDI skin staining, vs 19% without skin stains (p = 0.07). Working around and cleaning up liquid MDI represented a significant risk for asthma-like symptoms in both current smokers and nonsmokers; work with finished wood products did not. Asthma-like symptoms were associated with variable airflow limitation (odds ratio [OR], 5.0; confidence interval [CI], 1.4 to 18.7) and specific IgE to MDI-albumin (OR, 3.2; CI, 1.1 to 9.0), but not with skin prick tests to common aeroallergens (OR, 1.1; CI, 0.5 to 2.7). CONCLUSIONS: During the first 2 years of operation, in a plant designed and operated to control exposure to diisocyanates, the development of asthma-like symptoms was reported in a relatively high proportion of the employees who worked with liquid MDI. To prevent asthma symptoms among workers, careful control of respiratory tract exposures associated with liquid MDI is important, especially during cleanup activities. Strict limitation of skin contact with diisocyanates may also be necessary.     

Airway eosinophilia is associated with wheeze but is uncommon in children with persistent cough and frequent chest colds

The role of eosinophilic airway inflammation in the variant asthma syndromes of cough and chest colds is not well defined. We tested the hypothesis that children with persistent cough and chest colds have increased sputum eosinophils, similar to those with wheeze. The parents of 390 primary school children completed a symptoms questionnaire. Children with wheeze (n = 28), cough (n = 12), recurrent chest colds (n = 17), and no symptoms (control subjects, n = 26), underwent allergy skin prick tests, spirometry, hypertonic saline inhalation challenge, and sputum induction, and then completed a peak expiratory flow (PEF) and symptoms diary over a 2-mo period. Children with wheeze had significantly reduced PEF (p = 0.001) and higher sputum eosinophils when compared with the cough, chest cold, and control groups (3.1% versus 0.5%, 0%, 0%; p = 0.03). The prevalence of eosinophilic bronchitis (sputum eosinophils > 2.5%) was 45% in the wheeze group, which was significantly higher than the control group (9.35%, p = 0.04). Eosinophilic bronchitis was present in two children with cough (20%) and two with chest colds (15%, p > 0.05 versus control). In these groups, eosinophilic bronchitis was not associated with airway hyperresponsiveness (AHR) to hypertonic saline (p > 0.05). Children with cough and chest colds reported greater exposure to environmental tobacco smoke. In conclusion, this community-based survey of children with chronic respiratory symptoms has shown that wheeze is a good discriminator for the presence of eosinophilic bronchitis, and that persistent cough and recurrent chest colds without wheeze should not be considered a variant of asthma. Eosinophilic bronchitis did occur in a significant minority of these "variant asthma" syndromes.     

Excess incidence of asthma among Finnish cleaners employed in different industries.

The incidence and risk of asthma among female cleaners employed in different industries was explored. An increased risk of asthma has been associated with the cleaning profession, in some but not all studies. All Finnish females employed as cleaners and all those employed in administrative work were followed for asthma incidence through a record linkage in 1986-1998. An individual was defined as an "incident case of asthma" if they received rights for special reimbursement of asthma medication from the national health insurance or were recognized as having occupational asthma. Age-adjusted relative risks (RR) were estimated for cleaners in comparison with those employed in administrative work. There were 2,414 and 5,235 cases of asthma among the cleaners and administrative workers, respectively. The RR was 1.50 (95% confidence interval (CI) 1.43-1.57) in cleaners. The risk was increased in cleaners working in nearly all major sectors of economic activity, but cleaners employed by companies concerned with the manufacture of basic metals (RR 2.47; 95% CI 1.68-3.64) and food products (RR 2.19; 95% CI 1.69-2.85) had the highest risk. Only 25 of the "cases of asthma" among cleaners had been recognized as being occupational asthma. It could be concluded that cleaners have an increased risk of persistent adult-onset asthma. Factors inherent to the environment where cleaning is performed or differences in the cleaning agents used may explain the observed differences between industries.     

Occupational Respiratory Allergic Diseases in Healthcare Workers

Healthcare workers (HCWs) are exposed to a range of high and low molecular weight agents that are allergic sensitizers or irritants including cleaners and disinfectants, natural rubber latex, and various medications. Studies have shown that exposed HCWs are at risk for work-related rhinitis and asthma (WRA). Work-related rhinitis may precede development of WRA and should be considered as an early marker of WRA. Avoidance of causative exposures through control strategies such as elimination, substitution, engineering controls, and process modification is the preferred primary prevention strategy for preventing development of work-related allergic diseases. There is limited evidence for the effectiveness of respirators in preventing occupational asthma. If sensitizer-induced WRA is diagnosed, it is important to avoid further exposure to the causative agent, preferably by more rigorous application of exposure control strategies to the workplace. This review focuses on allergic occupational respiratory diseases in HCWs.     

Prevalence of nasal symptoms and their relation to self-reported asthma and chronic bronchitis/emphysema.

Little information is available on associations between rhinitis and chronic bronchitis/emphysema (CBE). Self-reported upper airway symptoms, asthma, and CBE were examined in 12,079 adults living in southern Sweden. The response rate was 70% (n=8,469), of whom 33% reported significant nasal symptoms: a blocked nose was reported by 21%; sneezing by 18%; nasal discharge by 17%; and thick yellow nasal discharge by 5.7%. Nasal symptoms and combined nasal and self-reported bronchial disease were generally more common among smokers than nonsmokers. There was little overlap between asthma and CBE, but 46% of those with asthma and 40% of those with CBE had significant nasal symptoms. Best predicting factors (odds ratios >3) for asthma and CBE were nasal symptoms due to exposure to animals and damp/cold air, respectively. One-third of an adult, southern Swedish population, had significant allergic and/or nonallergic nasal symptoms. Nasal symptoms were frequently found to coexist with both asthma and chronic bronchitis/emphysema, suggesting that pan-airway engagement is common in both diseases. Differing associations between types of nasal symptoms and allergic and irritant triggers of nasal symptoms, with regard to asthma and chronic bronchitis/emphysema, emphasize the different natures of these bronchial diseases.     

The outcome of asthma related to workplace irritant exposures: a comparison of irritant-induced asthma and irritant aggravation of asthma

STUDY OBJECTIVES: (1) To characterize workers' compensation claims accepted on the basis of new-onset asthma associated with accidental high respiratory irritant exposure at work; (2) to compare the frequency, characteristics, and outcomes in this group of workers to workers who were compensated for an exacerbation of preexisting asthma associated with accidental high respiratory irritant exposure at work. DESIGN: A retrospective review was performed of 469 asthma claims accepted by the Ontario Workers' Compensation Board (WCB) between 1984 and 1988. Among these, claims attributed to an accidental high respiratory irritant exposure at work were classified into two groups: one group with reported preexisting asthma prior to the exposure (accidental aggravation of asthma [AAA]) and another group with no previous history of asthma (irritant-induced asthma [IIA]). RESULTS: Of the 469 claims, 89 subjects (19%) had symptoms related to accidental high respiratory irritant exposure in the workplace; of these, 68 subjects (76%) had AAA, 12 subjects (13%) had IIA, and 9 subjects (10%) had possible IIA but were excluded from the analysis because of insufficient data. Those with IIA had a longer duration of work-attributed symptoms (mean, 219 +/- 208 days) than the subjects with AAA (mean, 32 +/- 38 days; p < 0.001). Nine subjects (75%) with IIA were no longer in the same work environment, while 47 subjects in the AAA group (71%) were still in the same work environment (p < 0.001). The most common triggering agent for subjects with IIA was an isocyanate spill; for those with AAA, the most common triggering agent was paint. CONCLUSIONS: The WCB-accepted claims related to accidental, high respiratory irritant exposure at work are more commonly assigned to the category of AAA than to IIA. IIA patients in this claimant group had a longer mean duration of work-attributed respiratory symptoms, perhaps due to a need for a larger (and thus less common) irritant exposure to induce asthma in previously normal subjects.     

Asthma and rhinitis in cleaning workers: a systematic review of epidemiological studies

Objective: This article presents a systematic review of epidemiological studies linking cleaning work and risk of asthma and rhinitis. Methods: Published reports were identified from PubMed covering the years from 1976 through June 30, 2012. In total, we identified 24 papers for inclusion in the review. The quality of studies was evaluated using the Strengthening of the Reporting of Observational Studies in Epidemiology (STROBE) statement checklist of 22 items for cross-sectional, cohort and case–control studies. Results: Increased risk of asthma or rhinitis has been shown in 79% of included epidemiological studies. In four studies the increased risk of asthma in cleaning workers was confirmed by objective tests, such as bronchial hyper-reactivity or airflow obstruction. Level of exposure to cleaning products, cleaning sprays, bleach, ammonia, mixing products and specific job tasks has been identified as specific causes of asthma and rhinitis. Conclusions: Possible preventive measures encompass the substitution of cleaning sprays, bleach and ammonia, avoidance of mixing products, the use of respiratory protective devices, worker education and medical surveillance.     

The use of household cleaning sprays and adult asthma: an international longitudinal study

RATIONALE: Cleaning work and professional use of certain cleaning products have been associated with asthma, but respiratory effects of nonprofessional home cleaning have rarely been studied. OBJECTIVES: To investigate the risk of new-onset asthma in relation to the use of common household cleaners. METHODS: Within the follow-up of the European Community Respiratory Health Survey in 10 countries, we identified 3,503 persons doing the cleaning in their homes and who were free of asthma at baseline. Frequency of use of 15 types of cleaning products was obtained in a face-to-face interview at follow-up. We studied the incidence of asthma defined as physician diagnosis and as symptoms or medication usage at follow-up. Associations between asthma and the use of cleaning products were evaluated using multivariable Cox proportional hazards or log-binomial regression analysis. MEASUREMENTS AND MAIN RESULTS: The use of cleaning sprays at least weekly (42% of participants) was associated with the incidence of asthma symptoms or medication (relative risk [RR], 1.49; 95% confidence interval [CI], 1.12-1.99) and wheeze (RR, 1.39; 95% CI, 1.06-1.80). The incidence of physician-diagnosed asthma was higher among those using sprays at least 4 days per week (RR, 2.11; 95% CI, 1.15-3.89). These associations were consistent for subgroups and not modified by atopy. Dose-response relationships (P < 0.05) were apparent for the frequency of use and the number of different sprays. Risks were predominantly found for the commonly used glass-cleaning, furniture, and air-refreshing sprays. Cleaning products not applied in spray form were not associated with asthma. CONCLUSIONS: Frequent use of common household cleaning sprays may be an important risk factor for adult asthma.     

Health-based selection for asthma, but not for chronic bronchitis, in pig farmers: an evidence-based hypothesis.

In cross-sectional surveys among pig farmers an elevated prevalence of chronic bronchitis is usually reported, but not of asthma, despite many factors promoting the manifestation of asthma. To investigate this apparent contradiction a postal questionnaire survey was performed among 239 pig farmers and 311 rural controls. Pig farmers reported an elevated prevalence of symptoms of chronic bronchitis (20.2 versus 7.7%, p<0.001), but not of asthma (5.9 versus 5.5% for chest tightness). Among pig farmers the use of disinfectants (prevalence odds ratio (POR) 9.4, 95% confidence interval (CI) 1.6-57.2 for quaternary ammonium compounds) and aspects of the disinfecting procedure were associated with the prevalence of asthma symptoms. Compared with controls, pig farmers reported fewer allergies to common allergens (4.6 versus 14.6%, p<0.001 for pollen) and fewer symptoms of atopy in childhood (9.9 versus 17.2, p<0.05 for one or more of four symptoms). Atopy in childhood was strongly associated with the prevalence of asthma symptoms (POR 4.1, 95% CI 2.2-7.7), but not with chronic bronchitis. Health-based selection of nonasthmatics for pig farming, which tends to mask a work-related hazard for asthma, is offered as an explanation for these results.     

Passive smoking exposure: a risk factor for chronic bronchitis and asthma in adults?

OBJECTIVE: The effects of passive smoke exposure on respiratory health are still under debate. Therefore, we examined the risk of respiratory symptoms related to passive smoke exposure among German adults within the European Community Respiratory Health Survey. METHODS: The questionnaire data of the population-based sample (n = 1,890) were analyzed. Multiple logistic regression models were carried out for current asthma (asthma symptoms or medication), chronic bronchitis (cough with phlegm for > or = 3 months per year), and wheezing as dependent variables, and self-reported exposure to passive smoke at home and at the workplace as independent variables after adjusting for city, age, gender, active smoking, and socioeconomic status as well as occupational exposure to dusts and/or gases. RESULTS: The relative odds for chronic bronchitis were significantly higher in subjects reporting involuntary tobacco smoke exposure in the workplace (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.16 to 3.11). Likewise, the adjusted OR for asthma was slightly elevated (OR, 1.51; 95% CI, 0.99 to 2.32). The risk of chronic bronchitis (OR, 3.07; 95% CI, 1.56 to 6.06), asthma (OR, 2.06; 95% CI, 1.07 to 3.97), and wheezing (OR, 2.12; 95% CI, 1.25 to 3.58) increased significantly with a daily exposure of > 8 h. CONCLUSION: The control of passive smoke exposure in the workplace might reduce the risk of respiratory symptoms independently of exposure to other airborne contaminants.     

Respiratory symptoms in children and exposure to pesticides.

In Lebanon, childhood asthma is an important disease and pesticides are commonly used. The objective of this study was to evaluate whether exposure to pesticides has chronic effects on the respiratory health of Lebanese children. A cross-sectional study was performed on children from a randomly selected sample of Lebanese public schools. Exposure to pesticides was evaluated by a standardised questionnaire and a residential exposure score, and respiratory symptoms were assessed by using the American Thoracic Society standardised questionnaire. A chronic respiratory disease was reported in 407 (12.4%) out of 3,291 children. The baseline difference in mean age was small but statistically significant. Any exposure to pesticides, including residential, para-occupational and domestic, was associated with respiratory disease and chronic respiratory symptoms (chronic phlegm, chronic wheezing, ever wheezing), except for chronic cough. Exposure to pesticides was associated with chronic respiratory symptoms and disease among Lebanese children.     

Symptoms related to obstructive sleep apnoea are common in subjects with asthma, chronic bronchitis and rhinitis in a general population

The purpose of this study was to examine the prevalence of self-reported snoring, apnoeas and daytime sleepiness in relation to chronic bronchitis, recurrent wheeze, physician-diagnosed asthma and rhinitis. This was a questionnaire study in a representative sample of a general population. The study was a part of the Obstructive Lung Disease in Northern Sweden Studies (OLIN). A total of 5424 subjects aged 20-69 years, born on the 15th day of each month, participated in the study. Eligible answers were obtained from 4648 subjects (85.7%). Having snoring as a problem was reported by 10.7%. Among subjects with chronic bronchitis it was reported by 25.9%, with recurrent wheeze by 21.3%, with physician-diagnosed asthma by 17.9%, and with rhinitis by 14.7%. Relatives' concerns of witnessed apnoea was reported by 6.8% of all subjects, while among subjects with chronic bronchitis it was reported by 18.1%, with recurrent wheeze by 17.1%, with physician-diagnosed asthma by 14.3%, and with rhinitis by 9.1%. After correction for age, gender and smoking habits, chronic bronchitis, rhinitis, asthma, and current smoking were significantly related, with snoring as a problem and with relatives' concern of witnessed apnoeas. Symptoms of daytime sleepiness were significantly related with concern of witnessed apnoeas, chronic bronchitis, snoring as a problem, recurrent wheeze and age 50-59 years. In conclusion, respiratory symptoms and conditions affecting mainly the lower respiratory tract, such as chronic bronchitis and asthma, were related with symptoms common in obstructive sleep apnoea.