Case report: a case of wood-smoke-related pulmonary disease

Association between one-year exposure to air pollution and the prevalence of pulmonary nodules in China

PM2.5is a well-known airborne hazard to cause various diseases. Evidence suggests that air pollution exposure contributes to the occurrence of pulmonary nodules. Pulmonary nodules detected on the computed tomography scans can be malignant or progress to malignant during follow-up. But the evidence of the association between PM2.5exposure and pulmonary nodules was limited. To examine potential associations of exposures to PM2.5and its major chemical constituents with the prevalence of pulmonary nodules. A total of 16 865 participants were investigated from eight physical examination centers in China from 2014 to 2017. The daily concentrations of PM2.5and its five components were estimated by high-resolution and high-quality spatiotemporal datasets of ground-level air pollutants in China. The logistic regression and the quantile-based g-computation models were used to assess the single and mixture impact of air pollutant PM2.5and its components on the risk of pulmonary nodules, respectively. Each 1 mg m-3increase in PM2.5(OR 1.011 (95% CI: 1.007-1.014)) was positively associated with pulmonary nodules. Among five PM2.5components, in single-pollutant effect models, every 1μg m-3increase in organic matter (OM), black carbon (BC), and NO3-elevated the risk of pulmonary nodule prevalence by 1.040 (95% CI: 1.025-1.055), 1.314 (95% CI: 1.209-1.407) and 1.021 (95% CI: 1.007-1.035) fold, respectively. In mixture-pollutant effect models, the joint effect of every quintile increase in PM2.5components was 1.076 (95% CI: 1.023-1.133) fold. Notably, NO3-BC and OM contributed higher risks of pulmonary nodules than other PM2.5components. And the NO3-particles were identified to have the highest contribution. The impacts of PM2.5components on pulmonary nodules were consistent across gender and age.These findings provide important evidence for the positive correlation between exposure to PM2.5and pulmonary nodules in China and identify that NO3-particles have the highest contribution to the risk.

Respiratory Health Status of Workers that Exposed to Welding Fumes at Lumut Shipyard

BACKGROUND AND OBJECTIVE

Welding fume exposure has led to the respiratory problems among welders including cough, phlegm, chest illnesses, nausea and fatigue. Inadequate ventilation during welding works causes the situation to worsen. Welding fumes can cause a decrease in lung function among welders. Chronic exposure will lead to other health effects especially COPD (Chronic Obstructive Pulmonary Disease). The objective of this study is to determine the exposure of welding fumes (Cd, Fe, Pb and Zn) towards respiratory health including lung function test (FEV1, FVC, FEV1/FVC, PEFR) of workers in Lumut shipyard, Perak.

MATERIAL AND METHODS

This research study the relationship between exposures of welding fumes towards lung function test among workers in Lumut shipyard, Perak. Lung function test was measured by spirometry among 30 welders and 31 non-welders. The concentration welding fume exposure was measured using OSHA ID-121 method. Sociodemographic data, respiratory symptoms and smoking habit data was analyzed based on the ATS 1987 questionnaire.

RESULTS

The mean concentration for Pb in welding fumes was 2.752 mg m-3 which is above 0.5 mg m-3 PEL-TWA. The FEV1 and FVC readings showed significant different between welders and non-welders (p = 0.001). Cough and phlegm symptoms showed significant different between welders and non-welders (p = 0.001). Welders had higher prevalence in smoking habit than the non-welders. Chest illnesses symptom showed an association with the smoking habit (p = 0.01).

CONCLUSION

There is relationship between welding fumes exposure on lung function test of workers in Lumut shipyard. Pb in welding fumes has high concentration and exceeded PEL-TWA level. The FEV1 and FVC in welders are lower than non-welder due to the fumes exposure. Welders showed higher respiratory symptoms than non-welders. Smoking habit is a contributing factor towards respiratory problem.

The role of environmental exposure to non-cigarette smoke in lung disease

Chronic exposure to household indoor smoke and outdoor air pollution is a major contributor to global morbidity and mortality. The majority of these deaths occur in low and middle-income countries. Children, women, the elderly and people with underlying chronic conditions are most affected. In addition to reduced lung function, children exposed to biomass smoke have an increased risk of developing lower respiratory tract infections and asthma-related symptoms. In adults, chronic exposure to biomass smoke, ambient air pollution, and opportunistic exposure to fumes and dust are associated with an increased risk of developing chronic bronchitis, chronic obstructive pulmonary disease (COPD), lung cancer and respiratory infections, including tuberculosis. Here, we review the evidence of prevalence of COPD in people exposed to non-cigarette smoke. We highlight mechanisms that are likely involved in biomass-smoke exposure-related COPD and other lung diseases. Finally, we summarize the potential preventive and therapeutic strategies for management of COPD induced by non-cigarette smoke exposure.

Respiratory health effects of occupational exposure to charcoal dust in Namibia

BACKGROUND

Charcoal processing activities can increase the risk of adverse respiratory outcomes.

OBJECTIVE

To determine dose-response relationships between occupational exposure to charcoal dust, respiratory symptoms and lung function among charcoal-processing workers in Namibia.

METHODS

A cross-sectional study was conducted with 307 workers from charcoal factories in Namibia. All respondents completed interviewer-administered questionnaires. Spirometry was performed, ambient and respirable dust levels were assessed in different work sections. Multiple logistic regression analysis estimated the overall effect of charcoal dust exposure on respiratory outcomes, while linear regression estimated the exposure-related effect on lung function. Workers were stratified according to cumulative dust exposure category.

RESULTS

Exposure to respirable charcoal dust levels was above occupational exposure limits in most sectors, with packing and weighing having the highest dust exposure levels (median 27.7 mg/m³, range: 0.2-33.0 for the 8-h time-weighted average). The high cumulative dust exposure category was significantly associated with usual cough (OR: 2.1; 95% CI: 1.1-4.0), usual phlegm (OR: 2.1; 95% CI: 1.1-4.1), episodes of phlegm and cough (OR: 2.8; 95% CI: 1.1-6.1), and shortness of breath. A non-statistically significant lower adjusted mean-predicted % FEV1 was observed (98.1% for male and 95.5% for female) among workers with greater exposure.

CONCLUSIONS

Charcoal dust levels exceeded the US OSHA recommended limit of 3.5 mg/m³ for carbon-black-containing material and study participants presented with exposure-related adverse respiratory outcomes in a dose-response manner. Our findings suggest that the Namibian Ministry of Labour introduce stronger enforcement strategies of existing national health and safety regulations within the industry.

Occupational and environmental lung disease

Occupational and environmental lung disease remains a major cause of respiratory impairment worldwide. Despite regulations, increasing rates of coal worker's pneumoconiosis and progressive massive fibrosis are being reported in the United States. Dust exposures are occurring in new industries, for instance, silica in hydraulic fracking. Nonoccupational environmental lung disease contributes to major respiratory disease, asthma, and COPD. Knowledge of the imaging patterns of occupational and environmental lung disease is critical in diagnosing patients with occult exposures and managing patients with suspected or known exposures.

Clinical Characteristics of Patients With Biomass Smoke-Associated COPD and Chronic Bronchitis, 2004-2014

Individuals with chronic obstructive pulmonary disease (COPD) associated with biomass smoke inhalation tend to be women born in rural areas with lifelong exposure to open fires while cooking, but can also include persons with prenatal and childhood exposure. Compared with individuals with COPD due to tobacco smoking, individuals exposed to biomass smoke uncommonly have severe airflow obstruction, low diffusing capacity of the lung for carbon monoxide (DLCO) or emphysema in high-resolution computed tomography (HRCT) but cough, phlegm and airway thickening and air trapping are very common. Autopsies of patients with COPD from biomass smoke exposure show increased pulmonary artery small vessel intimal thickening which may explain pulmonary hypertension, in addition to emphysema and airway disease. Research on similarities and differences in lung damage produced by exposure to biomass fuel smoke while cooking vs. smoking tobacco may provide new insights on COPD. As a public health problem, COPD caused by inhalation of smoke from burning solid fuel is as relevant as COPD caused by smoking tobacco but mainly affects women and children from disadvantaged areas and countries and requires an organized effort for its control. Improved vented biomass stoves are currently the most feasible intervention, but even more efficient stoves are necessary to reduce the biomass smoke exposure and reduce incidence of COPD among this population.

Lung function and incidence of chronic obstructive pulmonary disease after improved cooking fuels and kitchen ventilation: a 9-year prospective cohort study

BACKGROUND

Biomass smoke is associated with the risk of chronic obstructive pulmonary disease (COPD), but few studies have elaborated approaches to reduce the risk of COPD from biomass burning. The purpose of this study was to determine whether improved cooking fuels and ventilation have effects on pulmonary function and the incidence of COPD.

METHODS AND FINDINGS

A 9-y prospective cohort study was conducted among 996 eligible participants aged at least 40 y from November 1, 2002, through November 30, 2011, in 12 villages in southern China. Interventions were implemented starting in 2002 to improve kitchen ventilation (by providing support and instruction for improving biomass stoves or installing exhaust fans) and to promote the use of clean fuels (i.e., biogas) instead of biomass for cooking (by providing support and instruction for installing household biogas digesters); questionnaire interviews and spirometry tests were performed in 2005, 2008, and 2011. That the interventions improved air quality was confirmed via measurements of indoor air pollutants (i.e., SO₂, CO, CO₂, NO₂, and particulate matter with an aerodynamic diameter of 10 µm or less) in a randomly selected subset of the participants' homes. Annual declines in lung function and COPD incidence were compared between those who took up one, both, or neither of the interventions. Use of clean fuels and improved ventilation were associated with a reduced decline in forced expiratory volume in 1 s (FEV₁): decline in FEV₁ was reduced by 12 ml/y (95% CI, 4 to 20 ml/y) and 13 ml/y (95% CI, 4 to 23 ml/y) in those who used clean fuels and improved ventilation, respectively, compared to those who took up neither intervention, after adjustment for confounders. The combined improvements of use of clean fuels and improved ventilation had the greatest favorable effects on the decline in FEV₁, with a slowing of 16 ml/y (95% CI, 9 to 23 ml/y). The longer the duration of improved fuel use and ventilation, the greater the benefits in slowing the decline of FEV₁ (p<0.05). The reduction in the risk of COPD was unequivocal after the fuel and ventilation improvements, with an odds ratio of 0.28 (95% CI, 0.11 to 0.73) for both improvements.

CONCLUSIONS

Replacing biomass with biogas for cooking and improving kitchen ventilation are associated with a reduced decline in FEV₁ and risk of COPD.

TRIAL REGISTRATION

Chinese Clinical Trial Register ChiCTR-OCH-12002398.

Black bronchoscopy

A presence of black pigmentation involving the endobronchial tree is not uncommon. It was first described in the literature in association with occupational exposure in the early 1940s. However, in 2003, Packham and Yeow formally used the term black bronchoscopy to describe endobronchial metastasis from a malignant melanoma. Hyperpigmentation of the airway, however, is associated with multiple etiologies such as congenital disease, inborn errors of metabolism, infections, environmental exposures, neoplasm, and iatrogenic causes. Although the majority of these conditions are benign, a proper diagnosis is important for optimal management. In this article, we review the etiology of black bronchoscopy and discuss its presentations and current management guidelines.

Risk factors for tuberculosis

The risk of progression from exposure to the tuberculosis bacilli to the development of active disease is a two-stage process governed by both exogenous and endogenous risk factors. Exogenous factors play a key role in accentuating the progression from exposure to infection among which the bacillary load in the sputum and the proximity of an individual to an infectious TB case are key factors. Similarly endogenous factors lead in progression from infection to active TB disease. Along with well-established risk factors (such as human immunodeficiency virus (HIV), malnutrition, and young age), emerging variables such as diabetes, indoor air pollution, alcohol, use of immunosuppressive drugs, and tobacco smoke play a significant role at both the individual and population level. Socioeconomic and behavioral factors are also shown to increase the susceptibility to infection. Specific groups such as health care workers and indigenous population are also at an increased risk of TB infection and disease. This paper summarizes these factors along with health system issues such as the effects of delay in diagnosis of TB in the transmission of the bacilli.

Exposure to biomass smoke as a cause for airway disease in women and children

PURPOSE OF REVIEW

An estimated 3 billion people (about half the world's population) burn biomass fuel (wood, crop residues, animal dung and coal) for cooking and heating purposes exposing a large population, especially women and children, to high levels of indoor air pollution. Biomass smoke comprises gaseous air pollutants as well as particulate matter air pollutants, which have significant harmful effects.

RECENT FINDINGS

Exposure to biomass smoke is a major contributor to morbidity and mortality. Children, women and the elderly are most affected. Apart from poor lung growth seen in growing children, the risk of developing respiratory tract infections (both upper as well as lower) is greatly increased in children living in homes using biomass. Women who spend many hours cooking food in poorly ventilated homes develop chronic obstructive lung disease (COPD), asthma, respiratory tract infections, including tuberculosis and lung cancer. It has been argued that exposure to biomass fuel smoke is a bigger risk factor for COPD than tobacco smoking.

SUMMARY

Physicians need to be aware about the harmful effects of biomass smoke exposure and ensure early diagnosis and appropriate management to reduce the disease burden. More research needs to be done to study health effects due to biomass smoke exposure better. Reducing the exposure to biomass smoke through proper home ventilation, home design and, if possible, change of biomass to cleaner fuels is strongly recommended in order to reduce biomass smoke-induced mortality and morbidity.

Malondialdehyde and superoxide dismutase correlate with FEV(1) in patients with COPD associated with wood smoke exposure and tobacco smoking

Tobacco smoking is the primary risk factor for chronic obstructive pulmonary disease (COPD). However, recent epidemiological studies have established domestic exposure to wood smoke and other biomass fuels as additional important risk factors, characteristic in developing countries. Oxidative stress is one of the mechanisms concerned with pathogenesis of COPD. However, the molecular mechanisms involved in the onset and progress of COPD associated with biomass and specifically that derived from wood smoke exposure remain unknown. We analyzed the relationship between forced expiratory volume in first second (FEV(1)) with plasma malondialdehyde (MDA) concentration and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) in COPD patients associated with wood smoke (WSG; n = 30), tobacco smoking (TSG; n = 30), and healthy control subjects (HCG; n = 30). Differences between FEV(1) from WSG and TSG (58 +/- 22% and 51 +/- 24%, respectively) with HCG (100 +/- 6%) were observed (P < 0.01). Plasma MDA concentration was higher in both WSG and TSG (1.87 +/- 0.81 and 1.68 +/- 0.82 nmol/mL, respectively) compared with HCG (0.42 +/- 0.17 nmol/mL; P < 0.01). SOD activity showed a significant increase in both WSG and TSG (0.36 +/- 0.12 and 0.37 +/- 0.13 U/mL) compared with HCG (0.19 +/- 0.04 U/mL; P < 0.01). No differences were shown regarding GPx, GR, and GST activities between COPD and control groups. Inverse correlations were founded between MDA and SOD with FEV(1) in both COPD patients and control subjects (P < 0.001). These results indicate a role for oxidative stress in COPD associated with wood smoke similar to that observed with tobacco smoking in subjects who ceased at least 10 years previous to this study.

Imaging of small airways disease and chronic obstructive pulmonary disease

CT is a useful tool for identification of small airways diseases, and it can be used to classify these entities into inflammatory and constrictive bronchiolitis. Inflammatory forms of bronchiolitis include cellular bronchiolitis (usually caused by infection or aspiration), respiratory bronchiolitis, panbronchiolitis, and follicular bronchiolitis. Constrictive bronchiolitis may be caused by previous infection, toxic inhalation, collagen vascular disease, or transplantation. CT also helps categorize chronic obstructive pulmonary disease into emphysema predominant and airway predominant forms.

Pseudomediastinal fibrosis caused by massive lymphadenopathy in domestically acquired particulate lung disease

In this report, we describe a case of domestically acquired particulate lung disease (DAPLD) or "hut lung" in a 59-year-old woman of Moroccan descent who emigrated to the Netherlands, having lived in an rural area for most her life. She presented with obstructive lung disease and with signs of mediastinal fibrosis which were shown to be caused by massive enlargement of mediastinal lymph nodes. To the best of our knowledge, this is the first case of DAPLD from Morocco and the first report of a case of DAPLD mimicking mediastinal fibrosis.