Master Clinician and Public Health Practitioner: Selected Occupational and Environmental Pulmonary Cases

Occupational and environmental exposures contribute to the development and progression of most lung diseases, yet their impact is greatly under-recognized in clinical practice. Clinicians caring for patients with respiratory diseases should maintain a high index of suspicion for occupational and environmental contributing factors. Mastering occupational and environmental medicine clinical decision making requires specialized clinical skills. These skills include obtaining an appropriate work and exposure history; making an assessment of the magnitude and relevance of exposures and their contribution to a patient's respiratory disease; utilizing appropriate resources for evaluation and management of exposure-related disease; and considering socioeconomic and public health factors.

Trends and risk factors of mortality and disability adjusted life years for chronic respiratory diseases from 1990 to 2017: systematic analysis for the Global Burden of Disease Study 2017

OBJECTIVE

To describe the temporal and spatial trends of mortality and disability adjusted life years (DALYs) due to chronic respiratory diseases, by age and sex, across the world during 1990-2017 using data from the Global Burden of Disease Study 2017.

DESIGN

Systematic analysis.

DATA SOURCE

The Global Burden of Diseases, Injuries, and Risk Factors Study 2017.

METHODS

Mortality and DALYs from chronic respiratory diseases were estimated from the Global Burden of Disease Study 2017 using DisMod-MR 2.1, a Bayesian meta-regression tool. The estimated annual percentage change of the age standardised mortality rate was calculated using a generalised linear model with a Gaussian distribution. Mortality and DALYs were stratified according to the Socio-demographic index. The strength and direction of the association between the Socio-demographic index and mortality rate were measured using the Spearman rank order correlation. Risk factors for chronic respiratory diseases were analysed from exposure data.

RESULTS

Between 1990 and 2017, the total number of deaths due to chronic respiratorydiseases increased by 18.0%, from 3.32 (95% uncertainty interval 3.01 to 3.43) million in 1990 to 3.91 (3.79 to 4.04) million in 2017. The age standardised mortality rate of chronic respiratory diseases decreased by an average of 2.41% (2.28% to 2.55%) annually. During the 27 years, the annual decline in mortality rates of chronic obstructive pulmonary disease (COPD; 2.36%, uncertainty interval 2.21% to 2.50%) and pneumoconiosis (2.56%, 2.44% to 2.68%) has been slow, whereas the mortality rate for interstitial lung disease and pulmonary sarcoidosis (0.97%, 0.92% to 1.03%) has increased. Reductions in DALYs for asthma and pneumoconiosis have been seen, but DALYs due to COPD, and interstitial lung disease and pulmonary sarcoidosis have increased. Mortality and the annual change in mortality rate due to chronic respiratory diseases varied considerably across 195 countries. Assessment of the factors responsible for regional variations in mortality and DALYs and the unequal distribution of improvements during the 27 years showed negative correlations between the Socio-demographic index and the mortality rates of COPD, pneumoconiosis, and asthma. Regions with a low Socio-demographic index had the highest mortality and DALYs. Smoking remained the major risk factor for mortality due to COPD and asthma. Pollution from particulate matter was the major contributor to deaths from COPD in regions with a low Socio-demographic index. Since 2013, a high body mass index has become the principal risk factor for asthma.

CONCLUSIONS

Regions with a low Socio-demographic index had the greatest burden of disease. The estimated contribution of risk factors (such as smoking, environmental pollution, and a high body mass index) to mortality and DALYs supports the need for urgent efforts to reduce exposure to them.

Prevalence of Obstructive Lung Disease in Asymptomatic Gas Field Workers

Introduction Obstructive lung disease, if not managed appropriately and in a timely manner, increases morbidity and mortality. The aim of this study was to see an obstruction on spirometry reports of clinically asymptomatic oil and gas field workers. Methods In this retrospective observational study, spirometry reports performed at the pulmonary function laboratory of Ziauddin Hospital and University, Karachi, were reviewed. All reports were of the clinically asymptomatic employees of an oil and gas company in Pakistan, who presented for their routine assessment. Obstructive impairment was defined as a forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ratio of less than 0.7. Results Of the total of 199 spirometry reports, 197 (99%) were of male employees. The mean age of the employees was 30.52 ± 8.24 years and 46 (23.1%) employee were smokers. Obstruction was observed in 48 (24.1%) of the reports of the employees with 13 (27.1%) smokers and 35 (72.9%) non-smokers. No statistically significant association between obstruction and gender, age, and smoking was observed. Conclusion In this study, we observed obstructive impairment in around one-fourth of the otherwise clinically asymptomatic oil and gas field workers with no apparent impact of baseline smoking behavior.

Chronic Obstructive Pulmonary Disease in Farmers: A Systematic Review

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a significant public health problem but it is unclear whether agricultural work causes an increased risk of disease. The aim of this review was to study COPD risk among farmers and analyze occupational exposures in agricultural workplaces.

METHODS

A systematic literature search was conducted to identify epidemiological studies investigating COPD prevalence in farmers.

RESULTS

In the 14 studies reviewed, COPD prevalence ranged from 3% to 68% due to different characteristics of study population, working activities, case definition/diagnosis. Livestock farmers were at higher risk and significant associations were observed for exposure to organic dusts, endotoxins, mites, ammonia, and hydrogen sulfide.

CONCLUSIONS

Farming work was associated with greater risk of developing COPD. However, considering the several variables that may influence the disease prevalence in farmers, we suggest the adoption of a standardized research strategy.

Chronic bronchitis incidence in the extended cohort of Mayak workers first employed during 1948-1982

OBJECTIVES

This paper describes findings from the study of chronic bronchitis (CB) incidence after occupational exposure to ionising radiation among workers employed at Russian Mayak Production Association (PA) during 1948 and 1982 and followed up until 2008 based on 'Mayak Worker Dosimetry System 2008'.

METHODS

Analyses were based on 2135 verified cases among 21 417 workers. Rate ratios (RR) were estimated by categorical analysis for non-radiation and radiation factors. Excess rate ratios per Gy (ERR/Gy) of external or internal exposures with adjustments via stratification on other factors were calculated.

RESULTS

The interesting finding in relation to non-radiation factors was a sharp increase in the RR for CB incidence before 1960, which could be caused by a number of factors. Analyses restricted to the follow-up after 1960 revealed statistically significant associations of the CB incidence and external γ-ray radiation, ERR/Gy=0.14 (95% CI 0.02 to 0.28) having adjusted for sex, attained age, calendar period, plant, smoking status and lung α-particle dose, and internal α-particle radiation, ERR/Gy=1.14 (95% CI 0.41 to 2.18) having adjusted for sex, attained age, calendar period, plant, smoking status and lung γ-ray dose and ERR/Gy=1.19 (95% CI 0.32 to 2.53) having additionally adjusted for pre-employment occupational hazards and smoking index instead of smoking status.

CONCLUSIONS

Analyses of CB incidence in the study cohort identified positive significant association with occupational exposure to radiation: however, there are no similar studies of CB incidence in relation to radiation in other cohorts to date with which a meaningful comparison of the results could be made.

Occupational Risk Factors for COPD: A Case-Control Study

OBJECTIVES

The aim of this research was to examine the occupational risk factors for Chronic Obstructive Pulmonary Diseases (COPD) in a range of occupations.

METHODS

Eleven occupations involving different types of exposure were observed in this multicenter case-control study. Controls and cases were matched for sex, age and smoking. Multiple logistic regression analyses were used to estimate odds ratios (ORs).

RESULTS

A total of 1,519 participants were initially recruited between September 2004 and September 2012. After matching, 547 pairs were obtained. The mean age was 56.3 +/- 10.4 years. Smelter workers were the only ones with an increased risk of COPD in this study (OR = 7.6, p < 0.0001, 95% CI [4.5, 12.9]). Physical activity was protective (OR = 0.7), while living in the city was a risk (OR = 1.6). The main used metals were cast iron, aluminum and alloys. Molds and cores were mainly made from sand and synthetic resins. Machine maintenance (65.2%), molding (49.6%), finishing (41.1%) and casting (41.0%) were the most common activities. Almost all workers (95.1%) cleaned the floors and machines with a brush or compressed air.

CONCLUSIONS

This study demonstrates the importance of occupational factors in the genesis of COPD, especially among smelter workers. As with the fight against smoking-related disease, the removal or substitution of recognized hazardous agents is the best way of preventing the onset of COPD. This is why it is essential to continue research on its occupational risk factors.

[Early detection of COPD in occupational medicine in the Alpes-Maritimes]

INTRODUCTION

This study evaluated a standardized procedure aiming at early detection of COPD in a consecutive population of employees visiting occupational medicine.

METHODS

A total of 2818 employees were included by 22 occupational physicians in 5 centers. Respiratory symptoms, smoking status, occupational exposures and socioprofessional categories were collected. Subjects with at least one symptom and/or risk factor underwent spirometry.

RESULTS

In this population aged 39±12 years, 2603 patients were free of known asthma or COPD. The presence of at least one symptom was observed in 23.6 % of employees and was significantly associated with smoking status, occupational exposure to organic dust, gas fumes and vapors, and agriculture (P<0.0001). Airflow obstruction (FEV1/FVC < 0.70) was detected in 1.7 % of 1605 employees who underwent spirometry. With the inclusion of known COPD subjects (n=22), the prevalence reached 2.38 %. COPD was significantly associated with smoking intensity. Information on subsequent diagnosis was obtained in only two cases. The quality of spirometry was inadequate in 30 % of cases. Thirty-three percent of detected COPD subjects did not report any respiratory symptoms.

CONCLUSION

The strategy used in this study (specific questionnaire plus spirometry) allowed detection of a few cases of previously undiagnosed COPD. Occupational physicians need specific training in spirometry and a better follow-up of care pathways is required to obtain diagnostic confirmation.

Biopersistent granular dust and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Objective

Applying a systematic review to identify studies eligible for meta-analysis of the association between occupational exposure to inorganic dust and the development of chronic obstructive pulmonary disease (COPD), and conducting a meta-analysis.

Data Sources

Searches of PubMed and Embase for the time period 1970–2010 yielded 257 cross-sectional and longitudinal studies on people exposed to inorganic dust at the workplace with data on lung function. These studies were independently abstracted and evaluated by two authors; any disagreement was resolved by a third reviewer. Of 55 publications accepted for meta-analysis, 27 investigated the effects of occupational exposure to biopersistent granular dust (bg-dust).

Methods

A random effects meta-analysis allowed us to provide an estimate of the average exposure effect on spirometric parameters presented in forest plots. Between-study heterogeneity was assessed by using I² statistics, with I²>25% indicating significant heterogeneity. Publication bias was investigated by visual inspection of funnel plots. The influence of individual studies was assessed by dropping the respective study before pooling study-specific estimates.

Results

The mean FEV1 of workers exposed to bg-dust was 160 ml lower or 5.7% less than predicted compared to workers with no/low exposure. The risk of an obstructive airway disease—defined as FEV1/FVC < 70%—increased by 7% per 1 mg· m^-3 respirable bg-dust.

Conclusion

Occupational inhalative exposure to bg-dust was associated with a statistically significant decreased FEV1 and FEV1/FVC revealing airway obstruction consistent with COPD.

Obstructive pulmonary function impairment among Korean male workers exposed to organic solvents, iron oxide dust, and welding fumes

We evaluated spirometric obstructive pulmonary function impairment among workers who were occupationally exposed to organic solvents, iron oxide dust, or welding fumes. Data were collected from records of periodic health examinations of workers. In total, 448 Korean male workers were enrolled and classified into three exposure groups: exposure to organic solvents, iron oxide dust, or welding fumes. Logistic regression analysis was performed to evaluate the association between occupational exposure and pulmonary function. Compared to exposure to organic solvents, exposure to iron oxide dust was significantly associated with obstructive pulmonary function impairment (odds ratio [OR], 9.61; 95% confidence interval [CI], 2.20-41.97). The group exposed to welding fumes did not show a significantly higher OR compare to those exposed to organic solvents (OR, 2.83; 95% CI, 0.74-10.8). These results suggest that exposure to iron oxide dust has a greater association with obstructive pulmonary function impairment than exposure to organic solvents or welding fumes.

Semistructured black-box prediction: proposed approach for asthma admissions in London

Asthma is a global public health problem and the most common chronic disease among children. The factors associated with the condition are diverse, and environmental factors appear to be the leading cause of asthma exacerbation and its worsening disease burden. However, it remains unknown how changes in the environment affect asthma over time, and how temporal or environmental factors predict asthma events. The methodologies for forecasting asthma and other similar chronic conditions are not comprehensively documented anywhere to account for semistructured noncausal forecasting approaches. This paper highlights and discusses practical issues associated with asthma and the environment, and suggests possible approaches for developing decision-making tools in the form of semistructured black-box models, which is relatively new for asthma. Two statistical methods which can potentially be used in predictive modeling and health forecasting for both anticipated and peak events are suggested. Importantly, this paper attempts to bridge the areas of epidemiology, environmental medicine and exposure risks, and health services provision. The ideas discussed herein will support the development and implementation of early warning systems for chronic respiratory conditions in large populations, and ultimately lead to better decision-making tools for improving health service delivery.