Development of a job-task-exposure matrix to assess occupational exposure to disinfectants among US nurses.

OBJECTIVES: Occupational exposure to disinfectants is associated with work-related asthma, especially in healthcare workers. However, little is known about the specific products involved. To evaluate disinfectant exposures, we designed job-exposure (JEM) and job-task-exposure (JTEM) matrices, which are thought to be less prone to differential misclassification bias than self-reported exposure. We then compared the three assessment methods: self-reported exposure, JEM and JTEM. METHODS: Disinfectant use was assessed by an occupational questionnaire in 9073 US female registered nurses without asthma, aged 49-68 years, drawn from the Nurses' Health Study II. A JEM was created based on self-reported frequency of use (1-3, 4-7 days/week) of 7 disinfectants and sprays in 8 nursing jobs. We then created a JTEM combining jobs and disinfection tasks to further reduce misclassification. Exposure was evaluated in 3 classes (low, medium, high) using product-specific cut-offs (eg, <30%, 30-49.9%, ≥50%, respectively, for alcohol); the cut-offs were defined from the distribution of self-reported exposure per job/task. RESULTS: The most frequently reported disinfectants were alcohol (weekly use: 39%), bleach (22%) and sprays (20%). More nurses were classified as highly exposed by JTEM (alcohol 41%, sprays 41%, bleach 34%) than by JEM (21%, 30%, 26%, respectively). Agreement between JEM and JTEM was fair-to-moderate (κ 0.3-0.5) for most disinfectants. JEM and JTEM exposure estimates were heterogeneous in most nursing jobs, except in emergency room and education/administration. CONCLUSIONS: The JTEM may provide more accurate estimates than the JEM, especially for nursing jobs with heterogeneous tasks. Use of the JTEM is likely to reduce exposure misclassification.

Inflammatory potential in relation to the microbial content of settled dust samples collected from moisture-damaged and reference schools: results of HITEA study.

Aiming to identify factors causing the adverse health effects associated with moisture-damaged indoor environments, we analyzed immunotoxicological potential of settled dust from moisture-damaged and reference schools in relation to their microbiological composition. Mouse RAW264.7 macrophages were exposed to settled dust samples (n = 25) collected from moisture-damaged and reference schools in Spain, the Netherlands, and Finland. After exposure, we analyzed production of inflammatory markers [nitric oxide (NO), tumor necrosis factor-α (TNF-)α, interleukin (IL)-6, and macrophage inflammatory protein (MIP)2] as well as mitochondrial activity, viability, apoptosis, and cell cycle arrest. Furthermore, particle counts, concentration of selected microbial groups as well as chemical markers such as ergosterol, 3-hydroxy fatty acids, muramic acid, endotoxins, and glucans were measured as markers of exposure. Dust from moisture-damaged schools in Spain and the Netherlands induced stronger immunotoxicological responses compared to samples from reference schools; the responses to Finnish samples were generally lower with no difference between the schools. In multivariate analysis, IL-6 and apoptosis responses were most strongly associated with moisture status of the school. The measured responses correlated with several microbial markers and numbers of particles, but the most important predictor of the immunotoxicological potential of settled dust was muramic acid concentration, a marker of Gram-positive bacteria.

Occupational exposure to endocrine disruptors and lymphoma risk in a multi-centric European study.

BACKGROUND: Incidence rates of lymphoma are usually higher in men than in women, and oestrogens may protect against lymphoma. METHODS: We evaluated occupational exposure to endocrine disrupting chemicals (EDCs) among 2457 controls and 2178 incident lymphoma cases and subtypes from the European Epilymph study. RESULTS: Over 30 years of exposure to EDCs compared to no exposure was associated with a 24% increased risk of mature B-cell neoplasms (P-trend=0.02). Associations were observed among men, but not women. CONCLUSIONS: Prolonged occupational exposure to endocrine disruptors seems to be moderately associated with some lymphoma subtypes.

Healthy hire effect, job selection and inhalation exposure among young adults with asthma.

The aim of the present study was to assess whether asthma onset prior to entering the workforce influences whether a person holds a subsequent job with asthma-related inhalation exposures. The data of 19,784 adults from the European Community Respiratory Health Survey were analysed. For each respondent, a current or previously held job was linked to a job exposure matrix assigning high, low or no exposure to dust, gases or fumes. Jobs were also categorised according to the risk of exposures related to occupational asthma. Associations between asthma and subsequent occupational exposures were assessed using logistic regression models, with a random intercept for study centre and fixed adjustment for age, sex, type of study sample and smoking status. Of the respondents, 8% (n = 1,619) reported asthma with onset before completion of full-time education. This population was at decreased risk of having a job with high (odds ratio 0.79; 95% confidence interval 0.68-0.92) or low (0.91; 0.80-1.03) exposure to dust, gases or fumes. The associations were consistent across exposure types (dusts, gases or fumes) and for jobs with a high risk of occupational asthma. Adults with asthma onset prior to entering the workforce may be less likely to hold jobs involving inhalation exposures.

An international prospective general population-based study of respiratory work disability.

BACKGROUND: Previous cross-sectional studies have shown that job change due to breathing problems at the workplace (respiratory work disability) is common among adults of working age. That research indicated that occupational exposure to gases, dust and fumes was associated with job change due to breathing problems, although causal inferences have been tempered by the cross-sectional nature of previously available data. There is a need for general population-based prospective studies to assess the incidence of respiratory work disability and to delineate better the roles of potential predictors of respiratory work disability. METHODS: A prospective general population cohort study was performed in 25 centres in 11 European countries and one centre in the USA. A longitudinal analysis was undertaken of the European Community Respiratory Health Survey including all participants employed at any point since the baseline survey, 6659 subjects randomly sampled and 779 subjects comprising all subjects reporting physician-diagnosed asthma. The main outcome measure was new-onset respiratory work disability, defined as a reported job change during follow-up attributed to breathing problems. Exposure to dusts (biological or mineral), gases or fumes during follow-up was recorded using a job-exposure matrix. Cox proportional hazard regression modelling was used to analyse such exposure as a predictor of time until job change due to breathing problems. RESULTS: The incidence rate of respiratory work disability was 1.2/1000 person-years of observation in the random sample (95% CI 1.0 to 1.5) and 5.7/1000 person-years in the asthma cohort (95% CI 4.1 to 7.8). In the random population sample, as well as in the asthma cohort, high occupational exposure to biological dust, mineral dust or gases or fumes predicted increased risk of respiratory work disability. In the random sample, sex was not associated with increased risk of work disability while, in the asthma cohort, female sex was associated with an increased disability risk (hazard ratio 2.8, 95% CI 1.3 to 5.9). CONCLUSIONS: Respiratory work disability is common overall. It is associated with workplace exposures that could be controlled through preventive measures.

Occupational exposures and COPD: an ecological analysis of international data.

The occupational contribution to chronic obstructive pulmonary disease (COPD) has yet to be put in a global perspective. In the present study, an ecological approach to this question was used, analysing group-level data from 90 sex-specific strata from 45 sites of the Burden of Obstructive Lung Disease study, the Latin American Project for the Investigation of Obstructive Lung Disease and the European Community Respiratory Health Survey follow-up. These data were used to study the association between occupational exposures and COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II or above. Regression analysis of the sex-specific group-level prevalence rates of COPD at each site against the prevalence of occupational exposure and ever-smoking was performed, taking into account mean smoking pack-yrs and mean age by site, sex, study cohort and sample size. For the entire data set, the prevalence of exposures predicted COPD prevalence (0.8% increase in COPD prevalence per 10% increase in exposure prevalence). By comparison, for every 10% increase in the proportion of the ever-smoking population, the prevalence of COPD GOLD stage II or above increased by 1.3%. Given the observed median population COPD prevalence of 3.4%, the model predicted that a 20% relative reduction in the disease burden (i.e. to a COPD prevalence of 2.7%) could be achieved by a 5.4% reduction in overall smoking rates or an 8.8% reduction in the prevalence of occupational exposures. When the data set was analysed by sex-specific site data, among males, the occupational effect was a 0.8% COPD prevalence increase per 10% change in exposure prevalence; among females, a 1.0% increase in COPD per 10% change in exposure prevalence was observed. Within the limitations of an ecological analysis, these findings support a worldwide association between dusty trades and chronic obstructive pulmonary disease for both females and males, placing this within the context of the dominant role of cigarette smoking in chronic obstructive pulmonary disease causation.

A case-control study of the relation between plasma selenium and asthma in European populations: a GAL2EN project.

BACKGROUND: There is evidence that selenium levels are relatively low in Europe and may be falling. Low levels of selenium or low activity of some of the enzymes dependent on selenium have been associated with asthma. METHODS: The GA(2)LEN network has organized a multicentre case-control study in Europe to assess the relation of plasma selenium to asthma. The network compared 569 cases in 14 European centres with a diagnosis of asthma and reporting asthma symptoms in the last 12 months with 576 controls from the same centres with no diagnosis of asthma and no asthmatic symptoms in the last 12 months. RESULTS: All cases and controls were selected from the same population defined by age and place of residence. Mean plasma selenium concentrations among the controls ranged from 116.3 microg/l in Palermo to 67.7 microg/l in Vienna and 56.1 microg/l among the children in Oslo. Random effects meta-analysis of the results from the centres showed no overall association between asthma and plasma selenium [odds ratio (OR)/10 microg/l increase in plasma selenium: 1.04; 95% confidence interval (CI): 0.89-1.21] though there was a significantly protective effect in Lodz (OR: 0.48; 95% CI: 0.29-0.78) and a marginally significant adverse effect in Amsterdam (OR: 1.68; 95% CI: 0.98-2.90) and Ghent (OR: 1.35; 95% CI: 1.03-1.77). CONCLUSION: This study does not support a role for selenium in protection against asthma, but effect modification and confounding cannot be ruled out.

Eczema, atopy and allergen exposure in adults: a population-based study.

BACKGROUND: There are few published studies on geographical variation in prevalence of eczema in adults or its association with recognised risk factors for allergic disease. OBJECTIVE: To describe the geographical variation in prevalence of eczema in adults, assess the associations with sociodemographic risk factors, serum-specific IgE and IgG, and exposure to allergen. METHODS: A community-based sample of 8206 adults aged 27-56 years, in 25 European centres and Portland, USA, provided questionnaire information on symptoms of eczema. Serum-specific IgE to house dust mite (HDM), cat, grass and Cladosporium, and IgG and IgG4 to HDM and cat were measured. Mattress levels of mite and cat allergen were assessed. RESULTS: Overall prevalence of eczema was 7.1% (range between countries of 2.2-17.6%). Eczema was associated with female gender [odds ratio (OR) 1.25; 95% confidence interval (CI) (1.01-1.55)], family history of atopic disease (OR 1.43; 95% CI 1.18-1.74), IgE sensitization to at least one allergen (OR 1.50; 95% CI 1.19-1.90), particularly Cladosporium (OR 3.65; 95% CI 1.81-7.37), and total IgE. Eczema was negatively associated with age and no clear associations were observed with sibship size, mattress mite and cat allergen levels or with cat and HDM-specific IgG or IgG4. CONCLUSIONS: There is geographical variation in the prevalence of eczema in adults both within and between countries. Although the disease is associated with IgE sensitization, in this study it was not related to mattress mite or cat allergen levels.

Reported occupational respiratory diseases in Catalonia.

OBJECTIVES: A voluntary surveillance system was implemented in Catalonia (Spain) to ascertain the feasibility, incidence, and characteristics of occupational respiratory diseases and compare them with those of the compulsory official system. METHODS: In 2002, in collaboration with the Occupational and Thoracic Societies of Catalonia, occupational and chest physicians and other specialists were invited to report, on a bimonthly basis, newly diagnosed cases of occupational respiratory diseases. Information requested on each case included diagnosis, age, sex, place of residence, occupation, suspected agent, and physician's opinion on the likelihood that the condition was work related. Compulsory official system data derived from statistics on work related diseases for possible disability benefits declared by insurance companies, which are responsible for declaring these diseases to the Autonomous Government of Catalonia. RESULTS: Of 142 physicians seeing patients with occupational respiratory diseases approached, 102 (74%) participated. Three hundred and fifty nine cases were reported, of which asthma (48.5%), asbestos related diseases (14.5%), and acute inhalations (12.8%) were the most common. Physicians rated 63% of suspected cases as highly likely, 28% as likely, and 8% as low likelihood. The most frequent suspected agents reported for asthma were isocyanates (15.5%), persulphates (12.1%), and cleaning products (8.6%). Mesothelioma (5.9%) was the most frequent diagnosis among asbestos related diseases. The number of acute inhalations reported was high, with metal industries (26%), cleaning services (22%), and chemical industries (13%) being the most frequently involved. The frequency of occupational respiratory diseases recorded by this voluntary surveillance system was four times higher than that reported by the compulsory official system. CONCLUSIONS: The compulsory scheme for reporting occupational lung diseases is seriously underreporting in Catalonia. A surveillance programme based on voluntary reporting by physicians may provide better understanding of the incidence and characteristics of these diseases. Persulphates and cleaning products, besides isocyanates, were the most reported causes of occupational asthma. Metal industries and cleaning services were the occupations most frequently involved in acute inhalations with a remarkably high incidence in our register.

Asthma, chronic bronchitis, and exposure to irritant agents in occupational domestic cleaning: a nested case-control study.

BACKGROUND: Women employed in domestic cleaning are at increased risk for symptoms of obstructive lung disease, but the agents responsible are unknown. AIMS: To investigate common tasks and products in occupational domestic cleaning in relation to respiratory morbidity. METHODS: Case-control study in domestic cleaning women nested within a large population based survey of women aged 30-65 years; 160 domestic cleaning women with asthma symptoms, chronic bronchitis symptoms, or both and 386 without a history of respiratory symptoms were identified. Detailed exposures were evaluated for 40 cases who reported still having symptoms at the recruitment interview, and 155 controls who reported not having symptoms. All tasks performed and products used when cleaning houses were determined in a face-to-face interview. Lung function, methacholine challenge, and serum IgE testing were performed. Personal exposure measurements of airborne chlorine and ammonia were performed in a subsample. Associations between asthma, chronic bronchitis, and cleaning exposures were evaluated using multiple logistic regression analysis. RESULTS: Airborne chlorine (median level 0-0.4 ppm) and ammonia (0.6-6.4 ppm) were detectable during occupational domestic cleaning activities. Cases used bleach more frequently than controls; adjusted odds ratio (OR) for intermediate exposure was 3.3 (95% CI 0.9 to 11) and for high exposure 4.9 (1.5 to 15). Other independent associations included accidental inhalation of vapours and gases from cleaning agents and washing dishes. These associations were more pronounced for cases with asthma symptoms than for those with symptoms of chronic bronchitis, but were not related to sensitisation to common allergens. CONCLUSIONS: Asthma symptoms in domestic cleaning women are associated with exposure to bleach and possibly other irritant agents. The public health impact of the use of irritant cleaning products could be widespread since the use of these products is common both in the workplace and at home.

Smoking and occupation from the European Community Respiratory Health Survey.

BACKGROUND: Smoking is among the most important personal and modifiable risk factors for adverse health outcomes. The workplace offers a potentially effective venue for tobacco prevention programmes; identifying occupational groups with high smoking prevalence may assist in targeting such programmes. AIMS: To examine smoking prevalence among occupational groups in the European Union. METHODS: The European Community Respiratory Health Survey (ECRHS), a cross sectional health survey conducted in 1992-93, was used to examine smoking prevalence by occupation among 14 565 subjects from 30 centres in 14 participating countries. RESULTS: There was an approximately twofold range in smoking prevalence by occupation. For occupational groups with at least 50 subjects, the highest smoking prevalence was seen in metal making and treating for men (54.3%) and cleaners for women (50.7%). Increased smoking prevalence by occupation persisted after adjustment for age, country, and age at completion of education. Smoking was also increased among occupations with high exposure to mineral dust and gas or fumes. CONCLUSIONS: Smoking rates vary significantly by occupation. Prevention efforts in the workplace should focus on occupations with high smoking prevalence and large employment bases.

Asthma characteristics in cleaning workers, workers in other risk jobs and office workers.

Several studies have demonstrated an excess risk for asthma among cleaning workers. The aim of this analysis was to compare clinical, immunological and functional characteristics associated with asthma in cleaners and other occupational groups. Cleaners, workers exposed to high molecular weight (MW) agents, workers exposed to low MW agents, and office workers were identified from an international community-based epidemiological study. Influence of sex, smoking, age and atopy on the relationships with asthma was investigated. Rates of respiratory symptoms, bronchial hyperresponsiveness, atopic sensitisation and lung function were compared between asthmatics from the four groups (case-case analysis). The risk for asthma in workers exposed to low MW agents was higher among nonatopics than among atopics. Case-case analysis showed no major differences in asthma characteristics between cleaners and workers exposed to high or low MW agents. Asthmatic cleaners had less atopy, more chronic bronchitis and a lower lung function as compared to office workers. Asthma in cleaning workers showed many similarities with that in workers known to be at risk for occupational asthma. Atopic sensitisation did not seem to play an important role in cleaning-related asthma.

Incidence of asthma and its determinants among adults in Spain.

The objective was to measure the incidence of asthma and its determinants in Spain, where the prevalence of asthma is low to medium. A follow-up of subjects participating in the European Community Respiratory Health Survey (ECRHS) was conducted in 1998- 1999 (n = 1,640, 85% of those eligible). Subjects were randomly selected from the general population and were 20 to 44 yr old in 1991-1993. Time of follow-up was on average 6.75 yr (range, 5.3 to 7.9 yr). Asthma was defined as reporting ever having had asthma. The incidence of asthma was 5.53 (95% confidence interval, 4.28- 7.16) per 1,000 person-years (6.88 in females, 4.04 in males). Incidence was highest in subjects who at the baseline survey had bronchial hyperresponsiveness (incidence rate ratio [IRR], 3.85), in those with positive IgE against timothy grass (IRR, 3.16), and in females (IRR, 1.80). These results persisted after adjusting for respiratory symptoms at baseline. There was no significant association (p < 0.2) with high total serum IgE, atopy defined by reactivity to any allergen, smoking, occupational exposure, or maternal asthma. A sensitivity analysis using four definitions of population at risk yielded incidence rates varying from 5.53 to 1.50. In this population of subjects without self-reported asthma or asthma-type symptoms at baseline, bronchial hyperresponsiveness and IgE reactivity to grass appeared as the main determinants of new asthma.

Occupation, chronic bronchitis, and lung function in young adults. An international study.

We studied the relationship between occupational exposures, chronic bronchitis, and lung function in a general population survey in 14 industrialized countries, including 13,253 men and women aged 20 to 44 yr. We studied associations between occupational group, occupational exposures, bronchitis symptoms (cough and phlegm production for at least 3 mo each year), FEV(1), and nonspecific bronchial responsiveness (NSBR) separately in lifetime nonsmokers, cigarette smokers, and ex-smokers. Occupational exposure to vapors, gas, dust, or fumes, estimated with a job exposure matrix (JEM), was associated with chronic bronchitis among current smokers only (prevalence ratio (PR): 1.2 to 1.7). The interaction of occupational exposure with smoking, however, was not statistically significant (p > 0.1). Self-reported exposure was related to chronic bronchitis in all smoking groups. An increased risk for chronic bronchitis was found in agricultural, textile, paper, wood, chemical, and food processing workers, being more pronounced in smokers. Lung function and NSBR were not clearly related to occupational exposures. Findings were similar for asthmatic and nonasthmatic subjects. In conclusion, occupational exposures contributed to the occurrence of chronic (industrial) bronchitis in young adults. Fixed airflow limitation was not evident, probably due to the relatively young age of this population.

Effect of passive smoking on respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the European Community Respiratory Health Survey: a cross-sectional study.

BACKGROUND: Passive smoking is widespread, and environmental tobacco smoke contains many potent respiratory irritants. This analysis aimed to estimate the effect of passive smoking on respiratory symptoms, bronchial responsiveness, lung function, and total serum IgE in the European Community Respiratory Health Survey. METHODS: This analysis included data from 7882 adults (age 20-48 years) who had never smoked, from 36 centres in 16 countries. Information on passive smoking, respiratory symptoms, asthma, and allergic rhinitis was gathered through a structured interview. Spirometry and methacholine challenge were carried out, and total and specific IgE were measured. The effect of passive smoking was estimated by means of logistic and multiple linear regression for each country and combined across countries by random-effects meta-analysis. FINDINGS: In 12 of the 36 centres, more than half the participants were regularly involuntarily exposed to tobacco smoke. The prevalence of passive smoking in the workplace varied from 2.5% in Uppsala, Sweden, to 53.8% in Galdakao, Spain. Passive smoking was significantly associated with nocturnal chest tightness (odds ratio 1.28 [95% CI 1.02 to 1.60]), nocturnal breathlessness (1.30 [1.01 to 1.67]), breathlessness after activity (1.25 [1.07 to 1.47]), and increased bronchial responsiveness (effect -0.18 [-0.30 to -.05]). Passive smoking in the workplace was significantly associated with all types of respiratory symptoms and current asthma (odds ratio 1.90 [95% CI 0.90 to 2.88]). No significant association was found between passive smoking and total serum IgE. INTERPRETATION: Passive smoking is common but the prevalence varies widely between different countries. Passive smoking increased the likelihood of experiencing respiratory symptoms and was associated with increased bronchial responsiveness. Decreasing involuntary exposure to tobacco smoke in the community, especially in workplaces, is likely to improve respiratory health.

Influence of shift work and host factors on endotoxin-related acute peak flow changes.

There is limited knowledge about which internal and external factors influence respiratory effects of occupational endotoxin exposure. Relationships between endotoxin exposure, work-related respiratory symptoms, and acute peak flow changes were studied in 97 shift workers in the potato processing industry. For each worker, across-shift peak flow changes were determined for morning, afternoon, and night shifts. A higher endotoxin exposure was associated with an increased prevalence of work-related symptoms, a smaller peak expiratory flow (PEF) increase across the morning shift, and a larger PEF decrease across afternoon and night shifts. The largest effects occurred during the afternoon shift. No consistent differences between smokers and nonsmokers, and between atopics and nonatopics were observed. We conclude that endotoxin exposure in the potato processing industry is related to across-shift peak flow changes and the occurrence of work-related respiratory symptoms. The host factors smoking and atopy are not important confounding or effect-modifying factors in these relationships. In respiratory health studies among shift workers, it is important to investigate all work shifts before drawing definitive conclusions about exposure-response relationships.

Evaluation of chronic respiratory effects in the potato processing industry: indications of a healthy worker effect?

OBJECTIVE: To investigate the occurrence of chronic respiratory effects of exposure to organic dust in the potato processing industry. METHODS: Self reported chronic respiratory symptoms and spirometric lung function were assessed in a cross sectional study among 135 potato processing workers. A comprehensive study of current exposure to dust, endotoxin, and potato antigens had been performed previously. Workers were grouped into low and high exposure categories for each of the three exposure indices. Relations between exposure concentrations and respiratory health variables were investigated either by calculating prevalence rate ratios or by performing linear regression analyses. Atopy was assessed by measuring total immunoglobulin E (IgE) and specific IgE to five common aeroallergens in serum samples of workers. RESULTS: Evident relations between current exposure indices and respiratory health in the entire group were not found. Workers employed < or = 5 years showed a two-fold higher prevalence of respiratory symptoms, lower lung function, and higher endotoxin exposure than workers employed for > 5 years. Also, atopy was more prevalent in workers employed < or = 5 years. After stratification for duration of employment, negative effects of endotoxin on lung function among workers employed < or = 5 years were suggested. CONCLUSIONS: This study does not show chronic respiratory effects of exposure to organic dust in the potato processing industry, despite the fact that the levels of exposure to endotoxin found in this industry have been reported to be associated with decreases in lung function in other occupational settings. A likely explanation for not detecting apparent effects might be that many symptomatic workers drop out of this industry a few years after starting the job, suggesting a healthy worker effect.

Calculated changes in pH and pCO2 in arterial blood plasma assuming absence of ion and water exchange between plasma and erythrocytes during their equilibration with alveolar gas.

As a contribution to solving the problem of pH disequilibrium in arterial blood, the results of two modes of gas exchange in the lung have been calculated using an equilibrium state model of the blood. In both cases the HCO3-/Cl-exchange was assumed to occur after the gas exchange in the pulmonary capillaries. When the gas exchange was assumed to be dependent on intra-erythrocytic carbonic anhydrase, the plasma pH in the arterial blood increased. When plasma erythrocytes were assumed to equilibrate separately with the alveolar gas due to pressure of extra-erythrocytic carbonic anhydrase, plasma pH in the arterial blood decreased. In each case there was a slight increase in pCO2 after the blood had left the pulmonary capillaries.