Work-related respiratory health conditions among construction workers: a systematic narrative review

BACKGROUND

Emerging evidence in both developed and developing countries indicate that occupational health hazards and diseases among construction workers constitute a significant public health challenge. While occupational health hazards and conditions in the construction sector are diverse, a burgeoning body of knowledge is emerging about respiratory health hazards and diseases. Yet, there is a notable gap in the existing literature in terms of comprehensive syntheses of the available evidence on this topic. In light of this research gap, this study systematically reviewed the global evidence on occupational health hazards and related respiratory health conditions among construction workers.

METHODS

Using meta-aggregation, guided by the Condition (respiratory health conditions), Context (construction industry) and Population (construction workers) (CoCoPop) framework and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, literature searches were conducted on Scopus, PubMed, Web of Science and Google Scholar for relevant studies on respiratory health conditions affecting construction workers. Four eligibility criteria were used in scrutinising studies for inclusion. The quality of the included studies was assessed based on Joanna Briggs Institute's Critical Appraisal tool, while the reporting of the results was guided by the Synthesis Without Meta-analysis guidelines.

RESULTS

From an initial pool of 256 studies from the various databases, 25 studies published between 2012 and October 2022 were identified as meeting the inclusion criteria. In all, 16 respiratory health conditions were identified, with cough (ie, dry and with phlegm), dyspnoea/breathlessness and asthma emerging as the top three respiratory conditions among construction workers. The study identified six overarching themes of hazards that are associated with respiratory health conditions among construction workers. These hazards include exposure to dust, respirable crystalline silica, fumes, vapours, asbestos fibres and gases. Smoking and extended period of exposure to the respiratory hazard were found to increase the risk of contracting respiratory diseases.

CONCLUSIONS

Our systematic review indicates that construction workers are exposed to hazards and conditions that have adverse effects on their health and well-being. Given the considerable impact that work-related health hazards can have on the health and socioeconomic well-being of construction workers, we suggest that the implementation of a comprehensive occupational health programme is essential. Such a programme would extend beyond the mere provision of personal protective equipment and would incorporate a range of proactive measures aimed at controlling the hazards and mitigating the risk of exposure to the occupational health hazards.

Progressive massive fibrosis: An overview of the recent literature

This review provides an overview of literature addressing progressive massive fibrosis (PMF) from September 2009 to the present. Advances are described in understanding its pathophysiology, epidemiology of the occurrence of PMF and related conditions, the impact of PMF on pulmonary function, advances in imaging of PMF, and factors affecting progression of pneumoconiosis in dust-exposed workers to PMF. Basic advances in understanding the etiology of PMF are impeded by the lack of a well-accepted animal model for human PMF. Recent studies evaluating lung tissue samples and epidemiologic investigations support an important role for the silica component of coal mine dust in causing coal workers' pneumoconiosis and PMF in contemporary coal miners in the United States and for silica in causing silicosis and PMF in artificial stone workers throughout the world. Development of PMF is associated with substantial decline in pulmonary function relative to no disease or small opacity pneumoconiosis. In recent reports, computed tomography has had greater sensitivity for detecting PMF than chest x-ray. Magnetic resonance imaging shows promise in differentiating between PMF and lung cancer. Although PMF develops in dust-exposed workers without previously identified small opacity pneumoconiosis, the presence of small opacity pneumoconiosis increases the risk for progression to PMF, as does heavier dust exposure. Recent literature does not document any effective new treatments for PMF and new therapies to prevent and treat PMF are an important need.

Characterization of Silica Exposure during Manufacturing of Artificial Stone Countertops

Artificial stone is increasing in popularity in construction applications, including commercial and residential countertops. Eco-friendliness, durability, and resistance to staining, make artificial stone attractive to consumers. Health concerns have arisen during manufacturing of artificial stone due to increased incidence of silicosis after relatively short exposure. Three artificial stone samples (A, B, and C) and one natural granite sample were subjected to cutting and grinding in a controlled environment. Gravimetric analysis, X-Ray diffraction, and scanning electron microscopy with energy dispersive spectroscopy were employed to determine crystalline silica concentrations and particle morphology of bulk and respirable particles. Silica content of bulk dust from artificial samples A and B was 91%, sample C was <10%, while granite was 31%. Silica percent in the respirable fraction for samples A and B was 53% and 54%, respectively, while sample C was <5% and granite was 8%. Number concentrations for samples A and B were mainly in the nano-fraction, indicating potential for translocation of silica particles to other organs outside of the lungs. Respirable dust concentrations inside the chamber were well above Occupational Safety and Health Administration standards for all materials, indicating that confined-space exposures require ventilation to lower risks of acute silicosis regardless of the nature of the stone.

Silica-associated lung disease: An old-world exposure in modern industries

Despite silica dust exposure being one of the earliest recognized causes of lung disease, Australia, USA, Israel, Turkey and other countries around the world have recently experienced significant outbreaks of silicosis. These outbreaks have occurred in modern industries such as denim jean production, domestic benchtop fabrication and jewellery polishing, where silica has been introduced without recognition and control of the hazard. Much of our understanding of silica-related lung disease is derived from traditional occupations such as mining, whereby workers may develop slowly progressive chronic silicosis. However, workers in modern industries are developing acute and accelerated silicosis over a short period of time, due to high-intensity silica concentrations, oxidative stress from freshly fractured silica and a rapid pro-inflammatory and pro-fibrotic response. Appropriate methods of screening and diagnosis remain unclear in these workers, and a significant proportion may go on to develop respiratory failure and death. There are no current effective treatments for silicosis. For those with near fatal respiratory failure, lung transplantation remains the only option. Strategies to reduce high-intensity silica dust exposure, enforced screening programmes and the identification of new treatments are urgently required.

Silicosis in Artificial Quartz Conglomerate Workers

INTRODUCTION

Silicosis is a chronic progressive disease caused by inhalation of crystalline silica. Most cases develop in underground mine workers and in subjects involved in the extraction of natural stone (slate and granite). In view of the progressive emergence of new cases of silicosis in artificial quartz conglomerate workers, we performed a study to analyze the characteristics of silicosis produced by this new agent in Spain.

METHODS

The study consisted of a series of 96 cases of silicosis diagnosed according to international criteria during the period 2010-2017. We analyzed clinical, radiological, pathological and functional characteristics.

RESULTS

Mean age of participants was 45 years; 55% had simple silicosis and 45% had complicated silicosis. Ten patients were diagnosed with accelerated silicosis, with a mean age of 33 years. Mean time of exposure to conglomerates was 15 years, and 77% had not used appropriate protection measures. Half of the patients were asymptomatic and presented different classic forms on chest X-ray and chest high-resolution computed tomography, along with ground-glass images. No lung function changes were recorded.

CONCLUSIONS

Silicosis in artificial quartz conglomerate workers occurs in a young, actively employed population, a considerable percentage of whom present an accelerated form. They have few symptoms and no functional limitations. Protection measures are scarce. It is important to characterize these features to provide early diagnosis and implement the necessary preventive measures.

Epidemiology of silicosis: reports from the SWORD scheme in the UK from 1996 to 2017

OBJECTIVE

To document the demographic risk factors of workers reported to have silicosis in the UK.

METHODS

All cases of silicosis reported to the Surveillance of Work-related and Occupational Respiratory Disease (SWORD) scheme between January 1996 and December 2017 were classified into one of eight industry categories, and one of five age groups. In addition, to investigate whether there had been any temporal change, mean age and range at diagnosis was plotted for each year. From 2006, data were also available relating to the date of onset of symptoms, allowing a comparison between workers with and without respiratory symptoms.

RESULTS

For the period between 1996 and 2017, there were 216 cases of silicosis reported. The mean (range) age of those reported was 61 years (23-89), with the majority (98%) being male. Across all industries, 65% of cases were diagnosed in individuals of working age (<65 for men and <60 for women). Silicosis was reported in young workers across all industry groups, with around one in six of all silicosis cases affecting workers under the age of 46 years. There was no clear trend in age of diagnosis with time. Between 2006 and 2017, 81% of 108 workers with silicosis were reported to be symptomatic.

CONCLUSIONS

Silicosis remains an important health problem in the UK affecting workers of all ages across a wide range of industries traditionally associated with silica exposure.

Death in the New Town: Edinburgh's hidden story of stonemasons' silicosis

The building of the Edinburgh New Town, from the mid-18th to the mid-19th centuries, was a major advance in harmonious and elegant town planning. However, there is anecdotal evidence that it led to the occurrence of an epidemic of silicosis/tuberculosis among the stonemasons. We have reviewed contemporary accounts of the episode and early records of the understanding of silicosis. We have also studied the lung of a contemporary stonemason, preserved in the museum of the Royal College of Surgeons of Edinburgh, and confirmed the presence of silico-tuberculosis in it. The evidence shows that a major epidemic did occur, caused by a combination of factors. The size of the undertaking attracted many stonemasons to Edinburgh over a period of almost 100 years, intensively cutting and dressing stone. The principal stone worked was a very high-quartz sandstone, derived from the local Craigleith quarry, having properties that made it desirable for prestige buildings. However, even before the construction of the New Town, Craigleith sandstone was notorious for its dustiness and the Edinburgh stonemasons worked the stone in unventilated sheds. Stonemasons appeared to be aware of the risk of their trade, but little was known about preventive measures. It appears it was assumed that the risks to stonemasons disappeared after the Craigleith quarry closed, the employers emphasising (without evidence) the lack of health risks in other quarries, and the tragic episode appears to have been forgotten. However, we point to the continuing occurrence of silicosis among stonemasons to the present day; the importance of remembering such episodes is stressed lest the lessons of the past be forgotten.

Occupational lung diseases: from old and novel exposures to effective preventive strategies

Occupational exposure is an important, global cause of respiratory disease. Unlike many other non-communicable lung diseases, the proximal causes of many occupational lung diseases are well understood and they should be amenable to control with use of established and effective approaches. Therefore, the risks arising from exposure to silica and asbestos are well known, as are the means of their prevention. Although the incidence of occupational lung disease has decreased in many countries, in parts of the world undergoing rapid economic transition and population growth-often with large informal and unregulated workforces-occupational exposures continue to impose a heavy burden of disease. The incidence of interstitial and malignant lung diseases remains unacceptably high because control measures are not implemented or exposures arise in novel ways. With the advent of innovative technologies, new threats are continually introduced to the workplace (eg, indium compounds and vicinal diketones). In developed countries, work-related asthma is the commonest occupational lung disease of short latency. Although generic control measures to reduce the risk of developing or exacerbating asthma are well recognised, there is still uncertainty, for example, with regards to the management of workers who develop asthma but remain in the same job. In this Review, we provide recommendations for research, surveillance, and other action for reducing the burden of occupational lung diseases.