Interleukin 6 SNP rs1800797 associates with the risk of adult-onset asthma.

Interleukin 6 (IL6) is an inflammatory cytokine that has been suggested to have an important role in the pathogenesis of asthma. IL6 single-nucleotide polymorphisms (SNPs) have been associated with levels of IL6, and with childhood and prevalent adult asthma. A recent study also suggested that IL6 SNPs associate especially with atopic asthma. However, association of IL6 SNPs with adult-onset asthma has not been studied. In a population-based study of 467 incident adult-onset asthma cases and 613 disease-free controls from South Finland, we analyzed association of 6 tagging SNPs of the IL6 locus with the risk of adult-onset asthma and with atopy. Asthma was clinically diagnosed, and atopy was defined based on Phadiatop test. IL6 SNP rs1800797 associated with the risk of adult-onset asthma in a log additive model, with adjusted odds ratio (aOR) 1.31 (95% confidence interval 1.09-1.57), and especially with the risk of atopic adult-onset asthma when compared with non-atopic controls, aOR 1.46 (95% CI 1.12-1.90). This is the first study to show an association of IL6 with adult-onset asthma, and especially with atopic adult-onset asthma.

Shift work effects on serial PEF measurements for occupational asthma.

BACKGROUND: Diurnal variation (DV) affects lung function but the changes are thought to be related to sleep patterns rather than time of day. When diagnosing occupational asthma (OA), serial peak expiratory flow (PEF) measurements are the recommended first line investigation, but could be confounded by shift work. AIMS: The aim of the study was to investigate the effects of shift work on PEF measurements used for diagnosing OA. METHODS: PEF records containing more than one shift pattern with ≥ 4 days per shift were identified. OA diagnosis was based on an Oasys-2 score ≥ 2.51 and non-OA on having an alternative clinical diagnosis and Oasys-2 score <2.51. The mean area between curves (ABC) score, mean PEF DV and cross-shift PEF changes were calculated for each shift. RESULTS: Records from 123 workers with OA and 69 without OA satisfied inclusion criteria. In the OA group, PEF declined more on afternoon and night shifts than days (P < 0.001). The ABC score was lower in the OA group on night (P < 0.05) and afternoon shifts (P < 0.05) as compared with days, without significant differences in DV. Among those without OA, cross-shift PEF increased more on day shifts (mean + 25 l/min) than afternoon or night shifts (+1 l/min) (P < 0.001). The sensitivity for the ABC score and DV were good and similar across shifts, but specificity was reduced using DV (DV mean 39%; ABC 98%). CONCLUSIONS: PEF responses between work and rest show small differences according to shift type. The ABC score has a high sensitivity and specificity for all shifts; differences in DV have lower specificity.

Serial PEF measurement is superior to cross-shift change in diagnosing occupational asthma.

Cross-shift measurements of peak expiratory flow (PEF) are commonly employed in the diagnosis of occupational asthma, although evidence for this approach is lacking. The current paper presents an evaluation of the technique. Mean changes in PEF across morning/day shifts were compared between workers with occupational asthma, confirmed using specific challenge testing, and non-working asthmatics. Individuals were divided into a development set, used to identify the optimum cross-shift change for diagnosing occupational asthma, and an evaluation set, used to test the sensitivity and specificity of this value. Comparative analysis of serial PEF records was performed using the Oasys-2 computerised system. A cross-shift decrease in PEF of 5 L.min(-1) achieved acceptable specificity in the development set. Applied to the evaluation set, this cut-off had a specificity of 90.9% and a sensitivity of 50%. Sensitivity could not be improved without unacceptable compromise to specificity. Analysis of serial PEF records using linear discriminant analysis identified occupational asthma with a sensitivity of 83.3% and a specificity of 90.9%. Serial analysis using mean work/rest day PEF comparison had a sensitivity of 66.7% and a specificity of 100%. Cross-shift changes in PEF in morning/day-shift workers have poor sensitivity in diagnosing occupational asthma, and are inferior to serial techniques.

Respiratory and skin effects of exposure to wood dust from the rubber tree Hevea brasiliensis.

OBJECTIVES: Potential health effects related to wood dust from the rubber tree, which produces natural rubber latex, have not been previously investigated. The main aim of this study was to investigate the relations of rubber tree dust exposure to respiratory and skin symptoms, asthma and lung function. METHODS: A cross-sectional study was conducted among 103 workers (response rate 89%) in a rubber tree furniture factory and 76 office workers (73%) in four factories in Thailand. All participants answered a questionnaire and performed spirometry. Inhalable dust levels were measured in different work areas. RESULTS: Factory workers showed increased risk of wheezing, nasal symptoms and asthma compared to office workers. There was a dose-dependent increase in wheeze and skin symptoms in relation to dust level. Significantly increased risks of nasal symptoms (adj OR 3.67, 95% CI 1.45 to 9.28) and asthma (8.41, 1.06 to 66.60) were detected in the low exposure category. Workers exposed to ethyl cyanoacrylate glue had significantly increased risk of cough, breathlessness and nasal symptoms. There was dose-dependent reduction in spirometric lung function with wood dust level. CONCLUSIONS: This study provides new evidence that workers exposed to wood dust from the rubber tree experience increased risk of nasal symptoms, wheeze, asthma and skin symptoms and have reduced spirometric lung function. Exposure to cyanoacrylate is related to significantly increased respiratory symptoms. Results suggest that the furniture industry using rubber tree wood should implement appropriate exposure control measures to reduce wood dust exposure and cyanoacrylate glue exposure to protect their employees.

Fifteen-year trends in occupational asthma: data from the Shield surveillance scheme.

BACKGROUND: Trends of occupational asthma (OA) differ between regions depending on local industries, provisions for health and safety at the workplace and the availability of a reporting scheme to help in data collection and interpretation. AIM: To assess trends in OA in an industrialized part of the UK over a 15-year period. METHODS: Occupational and chest physicians in the West Midlands were invited to submit details of newly diagnosed cases with OA. Data were then transferred to the regional centre for occupational lung diseases for analysis. RESULTS: A total of 1461 cases were reported to the scheme. Sixty-eight per cent were males with mean (standard deviation) age of 44 (12) years. The annual incidence of OA was 42 per million of working population (95% CI = 37-45). OA was most frequently reported in welders (9%) and health care-related professions (9%) while < 1% of cases were reported in farmers. Isocyanates were the commonest offending agents responsible for 21% of reports followed by metal working fluids (MWFs) (11%), adhesives (7%), chrome (7%), latex (6%) and glutaraldehyde (6%). Flour was suspected in 5% of cases while laboratory animals only in 1%. CONCLUSIONS: Our data confirm a high annual incidence of OA in this part of the UK. MWFs are an emerging problem, while isocyanates remain the commonest cause. Incidence remained at a fairly stable background level with many small and a few large epidemics superimposed. Schemes like Midland Thoracic Society's Rare Respiratory Disease Registry Surveillance Scheme of Occupational Asthma could help in identifying outbreaks by linking cases at the workplace.

Respiratory effects of occupational exposures in a milk powder factory.

Ingestion of milk powder is a known cause of allergies in children, but the risks to respiratory health from exposure to inhaled milk powder have not been studied previously. The aim of the present study was to assess the effects of occupational exposures in a milk powder factory on respiratory symptoms and lung function. A cross-sectional study was conducted on 167 milk powder factory workers (response rate 77%) and 76 office workers (73%) from four factories in Thailand. All participants answered a questionnaire and performed spirometry. Measurements of concentrations of dust were used to give additional information on exposures. Mean respirable dust concentrations in the factory were 0.02-2.18 mg x m(-3). The risk of breathlessness and nasal symptoms were significantly increased in production and packing staff. The risk of skin symptoms was significantly increased in those adding vitamin mixture to milk powder. Factory workers showed significantly lower forced expiratory volume in one second measured as percentage of predicted value. The present study provides new evidence that workers exposed to milk powder by inhalation are at an increased risk of nasal symptoms, wheezing and breathlessness, and exhibit reduced spirometric lung function, even at relatively low air concentrations of milk dust.

Clinical investigation of an outbreak of alveolitis and asthma in a car engine manufacturing plant.

BACKGROUND: Exposure to metal working fluid (MWF) has been associated with outbreaks of extrinsic allergic alveolitis (EAA) in the USA, with bacterial contamination of MWF being a possible cause, but is uncommon in the UK. Twelve workers developed EAA in a car engine manufacturing plant in the UK, presenting clinically between December 2003 and May 2004. This paper reports the subsequent epidemiological investigation of the whole workforce. The study had three aims: (1) to measure the extent of the outbreak by identifying other workers who may have developed EAA or other work-related respiratory diseases; (2) to provide case detection so that those affected could be treated; and (3) to provide epidemiological data to identify the cause of the outbreak. METHODS: The outbreak was investigated in a three-phase cross-sectional survey of the workforce. In phase I a respiratory screening questionnaire was completed by 808/836 workers (96.7%) in May 2004. In phase II 481 employees with at least one respiratory symptom on screening and 50 asymptomatic controls were invited for investigation at the factory in June 2004. This included a questionnaire, spirometry and clinical opinion. 454/481 (94.4%) responded and 48/50 (96%) controls. Workers were identified who needed further investigation and serial measurements of peak expiratory flow (PEF). In phase III 162 employees were seen at the Birmingham Occupational Lung Disease clinic. 198 employees returned PEF records, including 141 of the 162 who attended for clinical investigation. Case definitions for diagnoses were agreed. RESULTS: 87 workers (10.4% of the workforce) met case definitions for occupational lung disease, comprising EAA (n = 19), occupational asthma (n = 74) and humidifier fever (n = 7). 12 workers had more than one diagnosis. The peak onset of work-related breathlessness was Spring 2003. The proportion of workers affected was higher for those using MWF from a large sump (27.3%) than for those working all over the manufacturing area (7.9%) (OR = 4.39, p<0.001). Two workers had positive specific provocation tests to the used but not the unused MWF solution. CONCLUSIONS: Extensive investigation of the outbreak of EAA detected a large number of affected workers, not only with EAA but also occupational asthma. This is the largest reported outbreak in Europe. Mist from used MWF is the likely cause. In workplaces using MWF there is a need to carry out risk assessments, to monitor and maintain fluid quality, to control mist and to carry out respiratory health surveillance.

Respiratory effects of exposure to methacrylates among dental assistants.

BACKGROUND: Case reports of occupational asthma in dental personnel have been published, but there is little data on the risk of respiratory disorders related to occupational exposure to methacrylates in dental assistants. The objective of this study was to investigate the relation of exposure to methacrylates to occurrence of respiratory symptoms and diseases among dental assistants. METHODS: A cross-sectional study of female dental assistants from the membership register of the Finnish Association of Dental Hygienists and Assistants was conducted in the Helsinki metropolitan area. A CATI was carried out to collect information on health and exposures. A total of 799 dental assistants participated (response rate 87%). RESULTS: Daily use of methacrylates was related to a significantly increased risk of adult-onset asthma (adjusted OR 2.65, 95% CI 1.14-7.24), nasal symptoms (1.37, 1.02-1.84), and work-related cough or phlegm (1.69, 1.08-2.71). Nasal symptoms showed a dose-response relation with increasing years of exposure to methacrylates, and those with >10 years of exposure had also increased risk of hoarseness, dyspnoea, and wheezing with dyspnoea. Dental assistants with a history of atopic diseases were particularly susceptible to exposure to methacrylates, the adjusted OR for adult asthma being in this group 4.18 (95% CI 1.02-28.55) and for nasal symptoms 2.11 (1.08-4.19). CONCLUSIONS: This study provides new evidence that the risk of adult-onset asthma, nasal symptoms and other respiratory symptoms increase significantly with daily use of methacrylates in dental assistants' work. The results suggest that exposure to methacrylates poses an important occupational hazard for dental assistants.

Impact of smoke-free workplace legislation on exposures and health: possibilities for prevention.

The aims of this study were to review experiences with national or statewide smoke-free workplace legislation and data on the occurrence of environmental tobacco smoke (ETS) exposure at work, to present the best estimates for health effects related to workplace ETS exposure, and to calculate corresponding population attributable fractions (PAFs) for respiratory and cardiovascular diseases for 14 European countries and the USA. Systematic searches of the Medline database were carried out, with a cut-off date of November 2005. PAFs for the main outcomes were calculated from the best disease-specific effect estimates and country-specific prevalences of work ETS exposure. Significant numbers of workers are exposed to ETS at work, i.e. approximately 7.5 million workers in 15 European Union countries and 24.6 million in the USA. Workplace ETS exposure is causally linked to lung cancer and coronary heart disease, and is related to an increased risk of asthma in adults and reduced birthweight in newborns. Relatively strong evidence links ETS exposure to chronic obstructive pulmonary disease and stroke. PAFs in Europe and the USA showed that, at current workplace ETS exposure prevalences, the public health impact is substantial. Experience of national and statewide smoke-free workplace legislation from different countries shows that such legislation leads to significant reductions in employees' environmental tobacco smoke exposure at work, as well as improvements in respiratory and cardiac health.

Scoring CT/HRCT findings among asbestos-exposed workers: effects of patient's age, body mass index and common laboratory test results.

We studied the effects of age, body mass index (BMI) and some common laboratory test results on several pulmonary CT/HRCT signs. Five hundred twenty-eight construction workers (age 38-80, mean 63 years) were imaged with spiral and high resolution CT. Images were scored by three radiologists for solitary pulmonary nodules, signs indicative of fibrosis and emphysema, ground glass opacities, bronchial wall thickness and bronchiectasis. Multivariate statistical analyses were adjusted for smoking and asbestos exposure. Increasing age, blood haemoglobin value and erythrocyte sedimentation rate correlated positively with several HRCT signs. Increasing BMI was associated with a decrease in several signs, especially parenchymal bands, honeycombing, all kinds of emphysema and bronchiectasis. The latter finding might be due to the suboptimal image quality in obese individuals, which may cause suspicious findings to be overlooked. Background data, including patient's age and body constitution, should be considered when CT/HRCT images are interpreted.

Smoking and asthma in adults.

Studies on the effect of smoking on adulthood asthma have provided contradictory results. The current authors conducted a population-based incident case-control study to assess the effects of current and past smoking on the development of asthma in adults. During a 2.5 yr study period, all new asthma cases clinically diagnosed (n=521) and randomly selected controls (n=932) from a geographically defined district in southern Finland were recruited. The risk of developing asthma was significantly higher among current smokers with an adjusted odds ratio (OR) of 1.33 (95% confidence interval 1.00-1.77) and among ex-smokers with an adjusted OR 1.49 (1.12-1.97) compared with never-smokers. Among current smokers, the risk increased up to 14 cigarettes x day(-1), and a similar trend was observed in relation to cumulative smoking. In conclusion, the current results support the hypothesis that smoking causes asthma in adulthood.

Effects of tobacco smoking on findings in chest computed tomography among asbestos-exposed workers.

This study examined the effects of smoking on the findings in chest computed tomography (CT) in 587 asbestos-exposed construction workers (11 females, 576 males, mean age 62 yrs; 18 never-smokers, 406 exsmokers and 163 current smokers). The workers were imaged with spiral CT and high-resolution CT. A total of 13 radiological signs were scored by three radiologists independently. The workers' medical data, smoking habits and occupational exposures were collected at an interview. The effects of smoking status and smoked pack-yrs (0-87.5) on the CT signs were studied using multivariate analysis adjusted for confounding factors. Smoking increased all emphysema signs and contributed to bronchial wall thickening. Smoking was negatively associated with curvilinear and septal lines as well as with parenchymal bands. In persons who had smoked <10 pack-yrs, smoking was positively related to paraseptal emphysema and to bronchial wall thickening and negatively related to septal lines, subpleural nodules and honeycombing. Smoking was related to several abnormal computed tomography signs even among those with relatively small exposure. Computed tomography can detect changes due to smoking at an early stage.

Indoor air pollution and respiratory health in the elderly.

People spend about > or = 80-90%, of their daily time indoors, elderly people especially at home. Thus, it is important to investigate possible health effects of indoor air pollutants and to consider their contributions to the total human exposure. This report summarises current knowledge on health effects of three common indoor air pollutants, respirable suspended particles, nitrogen dioxide and environmental tobacco smoke, with focus on the adults and the elderly. Preliminary findings on exposure distributions and health effects of these pollutants in older subjects of two panel studies carried out in Italian general populations will also be reported. The two indoor pollution studies were performed in the Po Delta area in North Italy (428 subjects and 140 houses investigated) and in Pisa in Central Italy (761 subjects and 282 houses investigated). Individuals aged > or = 65 yrs spent a significantly larger number of hours at home than the other age groups both in winter and in summer. A trend of higher occurrence of acute respiratory symptoms in the presence of environmental tobacco smoke was shown in comparison to the unexposed elderly both in winter (31 versus 29%) and summer (33 versus 16%). The occurrence of acute respiratory symptoms was consistently higher in relation to the high respirable suspended particles-index exposure compared to low exposure (33 versus 27%, in winter, 27 versus 21% in summer). Both the presence of environmental tobacco smoke at home and exposure to the high respirable suspended particles-index were associated with a decrease in the mean daily peak expiratory flow.

Immunoglobulin G antibodies against indoor dampness-related microbes and adult-onset asthma: a population-based incident case-control study.

Immunoglobulin G (IgG) antibodies against microbes related to indoor dampness problems have been used as potential biomarkers of fungal exposure in clinical investigations. There is limited information on their relation to asthma. We conducted a population-based incident case-control study to assess the risk of asthma in relation to specific IgG antibodies to eight dampness-related microbes: Aspergillus fumigatus, A. versicolor, Cladosporium cladosporioides, Fusarium oxysporum, Sporobolomyces salmonicolor, Stachybotrys chartarum, Streptomyces albus and Trichoderma citrinoviride. We recruited systematically all new cases of asthma during a 2.5-year study period and randomly selected controls from a source population of adults 21-63 years of age living in the Pirkanmaa Hospital District, South Finland. The clinically diagnosed case series consisted of 521 adults with newly diagnosed asthma and the control series of 932 controls selected randomly from the source population. IgG antibodies were analysed with ELISA. An increased risk of developing asthma in adulthood was significantly related to IgG antibodies to T. citrinoviride, but not to the other moulds. There was no evidence of a dose-response relation between the IgG antibody level and the risk of asthma. T. citrinoviride may play a role in the aetiology of adult-onset asthma or serve as an indicator of other causal factors.

Environmental tobacco smoke and health in the elderly.

The aims of this article are to synthesize the evidence on health effects of environmental tobacco smoke (ETS) in the elderly and to discuss questions for future research. Health effects are divided into aetiological and prognostic studies. There is convincing evidence that ETS causes lung cancer and coronary heart disease, both of which are diseases of the elderly. Several cross-sectional studies show increased occurrence of chronic respiratory symptoms and deficits in ventilatory lung function in relation to ETS exposure at home and/or at work. A limited number of studies have found significant relations between ETS exposure and asthma, chronic obstructive pulmonary disease (COPD), pneumococcal infections and stroke in the elderly. Longitudinal studies are needed before any definite conclusions can be made concerning ETS and noncarcinogenic respiratory diseases in the elderly. The potential role of environmental tobacco smoke exposure as a prognostic factor determining development of a pre-existing respiratory or heart disease is an important new area for research.

The short-term impact of national smoke-free workplace legislation on passive smoking and tobacco use.

OBJECTIVES: This study sought to evaluate the short-term impact of national smoke-free workplace legislation on employee exposure to environmental tobacco smoke at work and on employee smoking habits. METHODS: We performed 2 cross-sectional studies in 9 medium-sized and large Finnish workplaces, before and after implementation of national smoke-free workplace legislation. We assessed tobacco smoke exposure via questionnaire and indoor air nicotine measurements. RESULTS: Exposure to environmental tobacco smoke declined considerably after the legislation was implemented. Tobacco consumption among smokers diminished. Nicotine concentrations fell significantly. CONCLUSIONS: Legislation was more efficient than voluntary workplace-specific smoking restrictions in reducing passive smoking and cigarette consumption.

Mortality from occupational exposure to environmental tobacco smoke in Finland.

This article aimed to estimate the mortality from exposure to passive smoking at work in Finland. The estimation used statistics on causes of death, exposure prevalences, and risk ratios from epidemiologic studies. The attributable fractions of cause-specific mortality from passive smoking at work were 2.8% for lung cancer, 1.1% for chronic obstructive pulmonary disease, 4.5% for asthma, 3.4% for ischemic heart disease, and 9.4% for cerebrovascular stroke. Altogether, about 250 fatalities were estimated to have occurred in 1996. This is approximately 0.9% of the total mortality in the Finnish population in the relevant disease and age categories. The magnitude of mortality related to past occupational exposure to passive smoking is considerable. Preventive measures to reduce environmental tobacco smoke in the workplace will be a powerful means of reducing the high burden of respiratory and cardiovascular diseases.

Smoking during pregnancy in Finland: determinants and trends, 1987-1997.

OBJECTIVES: This study examined determinants of and trends in smoking during pregnancy in Finland from 1987 through 1997. METHODS: A repeated cross-sectional investigation of 694,926 women was conducted. RESULTS: The prevalence of smoking during pregnancy remained similar from 1987 through 1997 (at 15%). In 1997, prevalences of smoking were alarmingly high among young (37%), single (30%), and less educated (25%) women and among women living in northern (20%) and eastern (19%) Finland. These determinants were persistent over time, with the exception of an increase in regional differences. CONCLUSIONS: Despite increasing knowledge of adverse effects, smoking during pregnancy has not declined in Finland over the past decade.