Correlation between respiratory symptoms and pulmonary function in asbestos-exposed workers

Clinical-functional characteristics and risk of exacerbation and mortality among more symptomatic patients with chronic obstructive pulmonary disease: a retrospective cohort study

OBJECTIVES

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 classified chronic obstructive pulmonary disease (COPD) patients into more and less symptomatic groups. This study aimed to analyze the clinical characteristics, risk of future exacerbation and mortality among patients in more symptomatic group.

DESIGN

A retrospective cohort study.

SETTING

Data were obtained from patients enrolled in a database setup by Second Xiangya Hospital of Central South University.

PARTICIPANTS

1729 stable COPD patients listed from September 2017 to December 2019 in the database. The patients were classified into more and less symptomatic groups based on GOLD 2017 report.

OUTCOMES

All patients were followed up for 18 months. We collected baseline data and recorded the number of exacerbations and mortality during follow-up.

RESULTS

The more symptomatic patients were older, had higher Clinical COPD Questionnaire (CCQ) scores, more severe airflow limitation and higher number of exacerbations and hospitalizations in the past year (P < 0.05). Logistic regression showed that having more symptoms correlated with the CCQ scores and exacerbations in the past year (P < 0.05). After patients were followed up, there were higher numbers of exacerbations, hospitalizations and mortality rates in more symptomatic patients (P < 0.05). The multivariate model showed that age more than 65 years (OR = 2.047, 95% CI = 1.020-4.107) and COPD assessment test scores more than 30 (OR = 2.609, 95% CI = 1.339-5.085) were independent risk factors for mortality, whereas current smoker (OR = 1.565, 95% CI = 1.052-2.328), modified Medical Research Council scores (OR = 1.274, 95% CI = 1.073-1.512) and exacerbations in the past year (OR = 1.061, 95% CI = 1.013-1.112) were independent risk factors for exacerbation in more symptomatic patients (P < 0.05).

CONCLUSIONS

More symptomatic COPD patients have worse outcomes. In addition, several independent risk factors for exacerbation and mortality were identified. Therefore, clinicians should be aware of these risk factors and take them into account during interventions.

Physical activity in people with asbestos related pleural disease and dust-related interstitial lung disease: An observational study

This study aimed to measure the levels of physical activity (PA) in people with dust-related pleural and interstitial lung diseases and to compare these levels of PA to a healthy population. There is limited data on PA in this patient population and no previous studies have compared PA in people with dust-related respiratory diseases to a healthy control group. Participants with a diagnosis of a dust-related respiratory disease including asbestosis and asbestos related pleural disease (ARPD) and a healthy age- and gender-matched population wore the SenseWear(®) Pro3 armband for 9 days. Six-minute walk distance, Medical Outcomes Study 36-item short-form health survey and the Hospital Anxiety and Depression Scale were also measured. Fifty participants were recruited and 46 completed the study; 22 with ARPD, 10 with dust-related interstitial lung disease (ILD) and 14 healthy age-matched participants. The mean (standard deviation) steps/day were 6097 (1939) steps/day for dust-related ILD, 9150 (3392) steps/day for ARPD and 10,630 (3465) steps/day for healthy participants. Compared with the healthy participants, dust-related ILD participants were significantly less active as measured by steps/day ((mean difference 4533 steps/day (95% confidence interval (CI): 1888-7178)) and energy expenditure, ((mean difference 512 calories (95% CI: 196-827)) and spent significantly less time engaging in moderate, vigorous or very vigorous activities (i.e. >3 metabolic equivalents; mean difference 1.2 hours/day (95% CI: 0.4-2.0)). There were no differences in levels of PA between healthy participants and those with ARPD. PA was reduced in people with dust-related ILD but not those with ARPD when compared with healthy age and gender-matched individuals.

Correlation of respiratory symptoms and spirometric lung patterns in a rural community setting, Sindh, Pakistan: a cross sectional survey

BACKGROUND

Symptom-based questionnaires can be a cost effective tool enabling identification and diagnosis of patients with respiratory illnesses in resource limited setting. This study aimed to determine the correlation of respiratory symptoms and spirometric lung patterns and validity of ATS respiratory questionnaire in a rural community setting.

METHODS

This cross sectional survey was conducted between January - March 2009 on a sample of 200 adults selected from two villages of district Khairpur, Sindh, Pakistan. A modified version of the American thoracic society division of lung disease questionnaire was used to record the presence of respiratory symptoms. Predicted lung volumes i.e. forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and their ratio (FEV1/FVC) were recorded using portable spirometer.

RESULTS

In the study sample there were 91 (45.5%) males and 109 (54.5%) females with overall mean age of 34 years (±11.69). Predominant respiratory symptom was phlegm (19%) followed by cough (17.5%), wheeze (14%) and dyspnea (10.5%). Prevalence of physician diagnosed and self-reported asthma was 5.5% and 9.5% respectively. Frequency of obstructive pattern on spirometry was 28.72% and that of restrictive pattern was 19.68%. After adjustment for age, gender, socioeconomic status, spoken dialect, education, smoking status, height, weight and arsenic in drinking water, FVC was significantly reduced for phlegm (OR 3.01; 95% CI: 1.14 - 7.94), wheeze (OR 7.22; 95% CI: 2.52 - 20.67) and shortness of breath (OR 4.91; 95% CI: 1.57 - 15.36); and FEV1 was significantly reduced for cough (OR 2.69; 95% CI: 1.12 - 6.43), phlegm (OR 3.01; 95% CI: 1.26 - 7.16) and wheeze (OR 10.77; 95% CI: 3.45 - 33.6). Presence of respiratory symptoms was significantly associated with restrictive and/or obstructive patterns after controlling for confounders. Similar findings were observed through linear regression where respiratory symptoms were found to be significantly associated with decrements in lung volumes. Specificity and positive predictive values were found to be higher for all the symptoms compared to sensitivity and negative predictive values.

CONCLUSION

Symptoms based respiratory questionnaires are a valuable tool for screening of respiratory symptoms in resource poor, rural community setting.

Interpreting screening questionnaires: specific respiratory symptoms and their relationship to objective test results

OBJECTIVE

To better delineate the relationship between responses to screening respiratory symptom questionnaires and various pulmonary function test results.

METHODS

Spirometry, methacholine challenge, standardized questionnaires, smoking, medical, and work histories were recorded at initial and 5-year follow-up surveys among 411 participants. Percent-predicted forced expiratory volume in 1 second (ppFEV1), 5-year FEV1 decline, and proportion of methacholine responders (% hyper-responders) were compared with questionnaire responses utilizing generalized estimating equations modeling and analysis of variance.

RESULTS

Significant associations were found between ppFEV1 and cough, phlegm, dyspnea, or ever wheezing; between greater percentage of hyper-responders and dyspnea with wheezing, ever/persistent wheezing, or history of asthma/hay fever; and between accelerated FEV1 decline and new onset dyspnea with wheezing, phlegm, or persistent wheeze.

CONCLUSIONS

Particular respiratory symptoms reported on screening questionnaires are associated with specific physiologic abnormalities, enhancing questionnaire utility in workplace health surveillance.

Lung function decrement with arsenic exposure to drinking groundwater along River Indus: a comparative cross-sectional study

This study was designed to determine the association between chronic arsenic exposure through drinking groundwater and decrement in lung function, particularly among individuals who do not have signs of arsenic lesions, among an adult population. This was a comparative cross-sectional study conducted during the months of January to March 2009. One hundred participants ≥15 years of age in each group, i.e. exposed (≥100 μg/l) and unexposed (≤10 μg/l) to arsenic, determined by testing drinking water samples (using portable kits), were compared for effects on lung function using spirometry. A structured and validated questionnaire was administered. Examination for arsenic skin lesions was also done. There was a decline in the mean adjusted FEV1 of 154.3 ml (95% CI: -324.7, 16.0; p = 0.076), in mean adjusted FVC of 221.9 ml (95% CI: -419.5, -24.3; p = 0.028), and in FEV1/FVC ratio of 2.0 (95% CI: -25.3, 29.4; p = 0.884) among participants who were exposed to arsenic compared to those unexposed. A separate model comprising a total of 160 participants, 60 exposed to arsenic concentrations ≥250 μg/l and 100 unexposed at arsenic concentrations of ≤10 μg/l, showed a decrement in mean adjusted FEV1 of 226.4 ml (95% CI: -430.4, -22.4; p = 0.030), in mean adjusted FVC of 354.8 ml (95% CI: -583.6, -126.0; p = 0.003), and in FEV1/FVC ratio of 9.9 (95% CI: -21.8, 41.6; p = 0.539) among participants who were exposed to arsenic in drinking groundwater. This study demonstrated that decrement in lung function is associated with chronic exposure to arsenic in drinking groundwater, occurring independently, and even before any manifestation, of arsenic skin lesions or respiratory symptoms. The study also demonstrated a dose-response effect of arsenic exposure and lung function decrement.

Risk assessment of lung cancer and asbestosis in workers exposed to asbestos fibers in brake shoe factory in Iran

Chrysotile asbestos fiber, imported from Russia, is used mainly for manufacturing purposes in Iran and related risks in the form of asbestosis and cancer were studied. Occupational exposure of all male workers (61 persons) to asbestos in a brake shoe factory was monitored. Cumulative exposures were determined through multiplication of typical exposure and work history. Risk assessment of exposed workers was estimated by risk criteria recommended by the American Environmental Protection Agency. Measurement of lung function parameters such as forced expiratory volume in one second (FEV(1)), forced volume capacity (FVC) and FEV(1)/FVC of exposed workers were obtained. Unadjusted correlation and adjusted correlation analysis for support of the association between cumulative exposure (fiber/ml-yr) and lung function parameters were used. Exposure of majority of exposed group was far greater than the occupational exposure limits (0.1 fiber/ml) in the range of 0.06-8.06 fiber/ml. Cumulative exposures in the range of 0.02 to 110.77 fiber/ml-yr were obtained. According to the risk criteria stated by ATSDR, risk assessment of workers in term of fibrotic changes was predicted for at least 24.6 percent of the exposed subjects. Again, according to the lung cancer risk criteria stated by EPA, 59 percent of workers will have excess risk. Negative correlation between lung function parameters (FEV(1), FEV(1)/FVC) and cumulative exposures adjusted for age and BMI were significant (p<0.05).

Prevalence and risk of asthma symptoms among firefighters in São Paulo, Brazil: a population-based study

The firefighters are at increased risk of respiratory disease as a result of exposure to smoke and dust. The aim of this study was to determine the prevalence and risk associated with respiratory symptoms among city firefighters in São Paulo, Brazil.

METHODS

A cross-sectional study utilizing the European Community Respiratory Health Survey (ECRHS) questionnaire was administered to firefighters and police officers, in order to evaluate their respiratory symptoms.

RESULTS

Complete respiratory data were obtained from 1,235 firefighters and 1,839 police officers. Among the firefighters, there were 55.5% never-smokers, 22.4% current smokers and 18.2% former smokers (P < 0.05). Among the police officers, there were 63.4%, 18.6%, and 9.6% who were never-smokers, current smokers and former smokers (P < 0.05), respectively. Compared to police, firefighters experienced an increase in wheezing [OR = 1.63 (95% CI: 1.43-1.87)], wheezing with breathlessness [OR = 1.34 (95% CI: 1.10-1.64)], wheezing without a cold [OR = 1.60 (95% CI: 1.32-1.95)], waking with tightness in the chest [OR = 1.20 (95% CI: 1.02-1.42)], and rhinitis [OR = 1.12 (95% CI: 1.03-1.22)]. The prevalence of adult-onset asthma in never-smokers was 9.3% and 6.7% for firefighters and police officers [OR = 1.23 (95% CI: 1.01-1.56)]. An independent association was observed between years employed, smoking, history of rhinitis, and work as a firefighter and respiratory and nasal symptoms. We observed a high prevalence of asthma-like symptoms in firefighters who presented respiratory symptoms beginning immediately after firefighting.

CONCLUSION

These results suggest that the prevalence of respiratory symptoms and asthma in firefighters is higher than those in police officers. Work-as a firefighter, rhinitis and years employed were risk factors for respiratory symptoms of asthma.

Asbestosis in an asbestos composite mill at Mumbai: a prevalence study

BACKGROUND

Of an estimated 100,000 workers exposed to asbestos in India, less than 30 have been compensated. The reasons for such a small number are: refusal by management sponsored studies to grant medical certifications to workers suffering from occupational diseases, lack of training for doctors in diagnosis of occupational lung diseases, deliberate misdiagnosis by doctors of asbestosis as either chronic bronchitis or tuberculosis and the inherent class bias of middle class doctors against workers. The aim of the study was to identify workers suffering from Asbestosis (parenchymal and pleural non-malignant disease) among the permanent workers of the Hindustan Composites Factory and assess their disability and medically certify them, whereupon they could avail of their basic rights to obtain compensation and proper treatment.

METHODS

The study was conducted by the Occupational Health and Safety Centre and the Workers' Union. Asbestosis was diagnosed if they had an occupational history of asbestos exposure for at least 15 years and showed typical radiographic findings.

RESULTS

Of 232 workers in the factory, 181 participated in the survey. 22% of them had asbestosis. All the asbestos affected workers had at least 20 years of exposure. 7% had rhonchi, 34% had late basal inspiratory rates, 82% had more than 80% of Forced Expiratory Volume in the first second (FEV1)/Forced Vital capacity (FVC) ratio and 66% had FVC less than 80% of the predicted value. On radiology 7% had only pleural disease, 10% had both pleural and parenchymal disease and 82% had only parenchymal disease. The association of pleural disease with chest pain was statistically significant.

CONCLUSION

We found the prevalence of asbestosis among exposed workers to be less than that anticipated for the number of years of exposure due to "Healthy Worker Effect". We suggest that all affected asbestos workers (including those who have been forced to leave) in India be medically certified and compensated. We also recommend better control of asbestos use in India. We also implore the management to provide all information about the work process and its hazards, conduct medical checkups as mandated by law and give the medical records to the workers.

Non-malignant consequences of decreasing asbestos exposure in the Brazil chrysotile mines and mills

AIMS

To investigate the consequences of improvement in the workplace environment over six decades (1940-96) in asbestos miners and millers from a developing country (Brazil).

METHODS

A total of 3634 Brazilian workers with at least one year of exposure completed a respiratory symptoms questionnaire, chest radiography, and a spirometric evaluation. The study population was separated into three groups whose working conditions improved over time: group I (1940-66, n = 180), group II (1967-76, n = 1317), and group III (1977-96, n = 2137).

RESULTS

Respiratory symptoms were significantly related to spirometric abnormalities, smoking, and latency time. Breathlessness, in particular, was also associated with age, pleural abnormality and increased cumulative exposure to asbestos fibres. The odds ratios (OR) for parenchymal and/or non-malignant pleural disease were significantly lower in groups II and III compared to group I subjects (0.29 (0.12-0.69) and 0.19 (0.08-0.45), respectively), independent of age and smoking status. Similar results were found when groups were compared at equivalent latency times (groups I v II: 30-45 years; groups II v III: 20-25 years). Ageing, dyspnoea, past and current smoking, and radiographic abnormalities were associated with ventilatory impairment. Lower spirometric values were found in groups I and II compared to group III: lung function values were also lower in higher quartiles of latency and of cumulative exposure in these subjects.

CONCLUSIONS

Progressive improvement in occupational hygiene in a developing country is likely to reduce the risk of non-malignant consequences of dust inhalation in asbestos miners and millers.

Dispnéia crônica e alterações funcionais respiratórias em ex-trabalhadores com asbestose avaliados para concessão de benefício

INTRODUÇÃO: A dispnéia é um sintoma de difícil avaliação, principalmente nas doenças ocupacionais. OBJETIVO: Avaliar a relação entre presença e intensidade de dispnéia crônica, e sua repercussão funcional em ex-trabalhadores com asbestose na avaliação de disfunção e incapacidade. MÉTODO: Escores de dispnéia pelas escalas Medical Research Council modificada, American Medical Association de 1984 e 1993 e Baseline Dyspnea Index foram obtidos em 40 ex-trabalhadores com diagnóstico de asbestose, os quais foram também submetidos a espirometria, medidas da capacidade de difusão pulmonar do monóxido de carbono e testes de exercício cardiopulmonar incremental e submáximo. RESULTADO: Dispnéia esteve presente em 72,5% e 67,5% dos indíviduos de acordo com as escalas do Medical Research Council e American Medical Association de 1984, respectivamente e em apenas 37,5% e 31,6% dos pacientes de acordo com as escalas American Medical Association de 1.993 e Baseline Dyspnea Index. Houve melhor concordância entre as escalas Medical Research Council e American Medical Association de 1993, e American Medical Association de 1984 e American Medical Association de 1993 quando as graduações "ausente" e "leve" foram agrupadas. Não foi observada relação significativa entre dispnéia de acordo com cada uma das escalas e presença de anormalidades funcionais no repouso e/ou exercício. CONCLUSÃO: O nível de concordância entre as escalas de dispnéia varia significativamente em indivíduos com asbestose. Há falta de relação dos índices de dispnéia com variáveis que avaliam disfunção respiratória em repouso e exercício.

Respiratory symptoms and lung function of coke oven workers: a lung function surveillance system from 1990-2000

This study investigated the association of exposure to coke oven emissions with respiratory symptoms and with lung function. Data for respiratory symptoms and lung function were repeatedly collected from 764 male coke oven workers between 1990 and 2000. The data were analyzed cross-sectionally and longitudinally. Working in "Operation" increased the risk for cough (odds ratio [OR] = 2.37), phlegm (OR = 2.55), and shortness of breath (OR = 1.52). Cross-sectionally, each year of working in Operation was associated with a reduction in FEV1 of approximately 10 mL (P = 0.006) and in FVC of around 21 mL (P = 0.0001). From longitudinal analysis, each year of working in Operation was associated with an extra annual decline in FEV1 of 1.5 mL (P = 0.0012) and in FVC of around 1.8 mL (P = 0.0017). Exposure to coke oven emissions increased the risk for respiratory symptoms and adversely affected lung function.

Changing patterns in asbestos-induced lung disease

STUDY OBJECTIVES

To determine patterns in asbestos-induced lung diseases found in older, less exposed workers.

DESIGN

Review of a database evaluating lung function, smoking status, form of asbestos-induced lung disease, and radiograph abnormalities.

SETTING

Outpatient clinic.

PARTICIPANTS

A total of 3383 asbestos-exposed workers referred for independent medical evaluation, including control subjects who lacked asbestos-specific radiograph abnormalities (n = 243), subjects with low International Labor Organization (ILO) scores (n = 2,685), high ILO scores (n = 312), bronchogenic cancer (n = 63), and mesothelioma (n = 80). Of these, 3,327 workers have specific smoking status information and 3,312 workers have lung volume measures.

INTERVENTIONS

Chest radiographs were interpreted by a certified B-reader, and abnormalities were quantified according to the ILO scoring system. Spirometry and lung volume measurement were performed. Subjects completed a self-administered questionnaire that was reviewed at the time of examination. Control subjects were screened on two separate occasions at least 10 years apart to exclude subclinical or slowly progressive asbestos-induced lung disease.

MEASUREMENTS AND RESULTS

The mean age of the population was 65.1 +/- 9.9 years, and the latency was 41.4 +/- 10.1 years (+/- SD). Most subjects (41.8%) had normal pulmonary function. Obstruction was the most common pulmonary function abnormality (25.4%), followed by restriction (19.3%) and a mixed pattern (6.0%). Most subjects (79.4%) had low ILO scores. Benign pleural abnormalities were the only findings in 54% of subjects with low ILO score. Subjects with high ILO scores were older, smoked more, and had a longer latency than subjects with low ILO scores and control subjects. Smokers were younger, had a shorter latency, and had paradoxically greater ILO scores than nonsmokers. Subjects with bronchogenic cancer and mesothelioma had longer latencies than control subjects and subjects with benign asbestos-induced lung disease.

CONCLUSIONS

Asbestos-induced lung disease today is characterized by low ILO scores, long latencies, greater disease magnitude in smokers, and a normal or obstructive pattern of pulmonary function abnormality. Spirometric evaluation in the absence of lung volume measurements caused misclassification that resulted in overestimation of the presence of a restrictive pattern of pulmonary function.

Respiratory symptoms among HIV-seropositive individuals

STUDY OBJECTIVES

Recent evidence suggests that chronic or latent viral infection may be an important predisposing factor in the development of COPD among smokers. As such, understanding if HIV-seropositive smokers are at heightened risk for respiratory symptoms may have relevance with regard to COPD pathogenesis. The current study was done to systematically identify the prevalence of respiratory symptoms among an HIV-seropositive population and to identify associated clinical features.

DESIGN AND SETTING

Cross-sectional analysis at an academic medical center.

PARTICIPANTS

Three hundred twenty-seven HIV-seropositive individuals without a history of AIDS-related pulmonary complications. Fifty-two HIV-negative individuals with a similar age and smoking history served as a comparison group.

MEASUREMENTS

Administration of the American Thoracic Society Division of Lung Diseases respiratory questionnaire, and pulmonary function studies.

RESULTS

Respiratory symptoms including dyspnea (41.6% vs 7.7%), cough (40% vs 25%), and phlegm production (41.9% vs 23.1%) were extremely common in the HIV-group and significantly more common than in the HIV-negative group. Current or prior cigarette smoking was the most important predictor of respiratory symptoms among the HIV-seropositive group. The use of the antiretroviral agent lamivudine was associated with a significant reduction in dyspnea.

CONCLUSION

HIV-seropositive individuals are at increased risk for the development of respiratory symptoms even prior to the onset of AIDS-related pulmonary complications. This may reflect a heightened susceptibility to the effects of cigarette smoking.

Non-malignant asbestos-related diseases in Brazilian asbestos-cement workers

BACKGROUND

Production of asbestos-cement products in Brazil started in the 1940s, peaked in the 60-70s and is still an active industry. This study was designed to assess the non-malignant effects of asbestos exposure in the asbestos-cement industry in Brazil.

METHODS

A group of 828 former asbestos-cement workers enrolled in a cross-sectional and cohort study of respiratory morbidity, submitted to a detailed occupational history, respiratory symptoms questionnaire, spirometry, PA chest x-ray, and high resolution computed chest tomography (HRCT). Asbestos exposure was assessed by years of exposure, cumulative exposure (a semi-quantitative method), and latency time from first exposure. Asbestosis and pleural thickening were assessed according to HRCT criteria.

RESULTS

Asbestosis was present in 74 (8.9%) and pleural thickening in 246 (29.7%). Using the HRCT as the "best available evidence", it was shown that were more false negatives than false positives in the x-ray readings for parenchymal (21.6% false negatives, 4.2% false positives) and pleural (26.0% false negatives, 14.4% false positives) diseases due to asbestos. Latency time from first exposure was the best predictor for both asbestosis and pleural thickening. Subjects in the higher exposure groups presented lower levels of lung function. Obstructive defects were significantly related to smoking, shortness of breath, body mass index, and age, whereas restrictive defects were related to asbestosis, shortness of breath, and latency time. Chronic bronchitis increased with latency time in the three smoking groups and was significantly related to pleural thickening (OR 1.56 (1.00-2.42)). Shortness of breath was significantly associated with body mass index and pleural thickening (OR 1.30 (1.24-2.09)).

CONCLUSIONS

Pleural thickening and asbestosis showed a significant association with latency time and exposure. FVC and FEV(1) decreased across increasing profusion with an added effect of pleural thickening. There was a significant and independent effect of exposure on lower levels of FVC and FEV(1). Obstructive defects were mainly related to smoking and restriction to asbestosis. Dust exposure and smoking were synergistic in increasing chronic bronchitis and shortness of breath report. Shortness of breath report was also related to pleural thickening and higher body mass index.

Chest pain in asbestos-exposed individuals with benign pleural and parenchymal disease

Many asbestos-exposed individuals complain of chest pain for which there is no clear explanation. To determine whether chest pain is associated with the presence of benign pleural or parenchymal disease on chest radiograph, we studied 1,280 subjects undergoing surveillance because of prior asbestos exposure at Wittenoom, Western Australia. All subjects completed the Rose questionnaire on chest pain and this revealed 556 subjects (43%) who experienced some chest pain. A posterior-anterior chest radiograph was performed at the same clinic visit and was subsequently graded independently by two experienced readers for diffuse parenchymal disease and pleural disease. Logistic regression models adjusted for sex, age, and cumulative asbestos exposure indicated that the presence of chest pain was significantly associated with the presence of both benign pleural disease and diffuse parenchymal disease. Further analysis after stratification of chest pain into nonanginal and anginal pain showed that there was a significant association between anginal pain and the presence of pleural and parenchymal asbestos-induced radiologic abnormalities and an association of nonanginal pain with parenchymal disease. We conclude that radiographic evidence of either parenchymal or pleural disease in subjects exposed to asbestos is significantly related to the presence of chest pain, particularly anginal pain.

Acute respiratory symptoms in workers exposed to vanadium-rich fuel-oil ash

BACKGROUND

Occupational exposure to fuel-oil ash, with its high vanadium content, may cause respiratory illness. It is unclear, however, what early acute health effects may occur on the pathway from normal to compromised respiratory function.

METHODS

Using a repeated measures design, we studied prospectively 18 boilermakers overhauling an oil-fired boiler and 11 utility worker controls. Subjects completed a respiratory symptom diary five times per day by using a 0-3 scale where 0=symptom not present, 1=mild symptom, 2=moderate symptom, and 3=severe symptom. Daily symptom severity was calculated by using the highest reported score each day for upper and lower respiratory symptoms. Daily symptom frequency was calculated by summing all upper or lower airway symptom reports, then dividing by number of reporting times. Respiratory symptom frequency and severity were analyzed for dose-response relationships with estimated vanadium and PM(10) doses to the lung and upper airway by using robust regression.

RESULTS

During the overhaul, 72% of boilermakers reported lower airway symptoms, and 67% reported upper airway symptoms. These percentages were 27 and 36 for controls. Boilermakers had more frequent and more severe upper and lower respiratory symptoms compared to utility workers, and this difference was greatest during interior boiler work. A statistically significant dose-response pattern for frequency and severity of both upper and lower respiratory symptoms was seen with vanadium and PM(10) in the three lower exposure quartiles. However, there was a reversal in the dose-response trend in the highest exposure quartile, reflecting a possible healthy worker effect.

CONCLUSIONS

Boilermakers experience more frequent and more severe respiratory symptoms than utility workers. This is most statistically significant during boiler work and is associated with increasing dose estimates of lung and nasal vanadium and PM(10).

Dyspnoea is associated with pulmonary function impairment in exposed workers

This study aimed to evaluate the prevalence of dysponea and its predictors in studies on several working male groups in British Columbia (BC), Canada (cedar sawmill, grain elevator, pulpmill, and aluminum smelter workers), and Tuscany (T), Italy, (shoe and furniture makers, millers, bakers, and pharmaceutical workers). We performed cross-sectional health studies (interviews and pulmonary function tests) for 2498 BC and 1474 T workers exposed to air contaminants, and 1110 BC and 243 T controls. Similar questionnaires and the same definitions were used in BC and in T. Pulmonary function tests were also performed. The participation rates were >92% in BC workers and 82% in T workers. The overall prevalence of moderate dyspnoea was not different in exposed BC and T workers in comparison with controls. Slight dyspnoea was significantly more frequent in BC workers, but not in T workers, with respect to controls. After adjusting for age, body mass index (BMI), smoking, current asthma, and chronic bronchitis, forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were found to be significantly associated with slight and moderate dyspnoea in BC workers, and slight dyspnoea in T workers. Isolated dyspnoea is associated with reduction in FEV1 and FVC in working populations, after adjusting for potentially confounding variables.

Longitudinal pattern of reported respiratory symptoms and accelerated ventilatory loss in asbestos-exposed workers

Studies investigating the relation between respiratory symptoms and change in ventilatory function have been limited by use of reported symptoms at a single point in time. To assess the relation between the longitudinal pattern of reported cough, phlegm, wheeze, and dyspnea and ventilatory loss, we prospectively investigated changes in FVC and FEV1 associated with development, resolution, or persistence of these symptoms over a 3- to 5-year period in 446 asbestos-exposed workers. Longitudinally reported symptoms changed frequently, with 52 to 61% of subjects reporting a specific symptom noting resolution or development of that symptom during follow-up. Initially reported symptoms were not predictive of accelerated loss of FVC or FEV1. In contrast, development of any new respiratory symptom, and to a lesser extent persistence of symptoms during follow-up, were associated with significantly greater ventilatory losses compared with asymptomatic individuals, ranging from 28 mL/yr in FEV1 for newly developed dyspnea, to 67 mL/yr in FVC for developed wheeze (p < 0.01). We conclude that development or persistence of respiratory symptoms over time, rather than the presence of symptoms per se, is predictive of future ventilatory loss. Recognition of interval changes in symptom reporting during surveillance of asbestos-exposed workers may effectively identify groups at risk for progressive ventilatory impairment.