Predictors of psychological stress in silica-exposed workers in the artificial stone benchtop industry

Global scenario of silica-associated diseases: A review on emerging pathophysiology of silicosis and potential therapeutic regimes

Silicosis is an occupational fibrotic lung disease caused by exposure to respirable crystalline silica dust particles produced during industrial activities. Other crystalline silica-induced pulmonary disorders include a predisposition to mycobacterial infections, obstructive airway diseases, idiopathic pulmonary fibrosis, and lung cancer. This review paper discusses the burden of silicosis and associated co-morbidities in developed as well as developing countries globally using the published data of various government agencies, related organizations, and epidemiological findings. Moreover, it sheds light on diverse mechanisms of silicosis, outlining molecular events and peculiar alterations in lung parenchyma leading to this occupational lung disease. Evaluation of pathophysiological mechanisms could aid in the identification of novel target molecules and treatments; to date, there is no curative treatment for silicosis. In recent periods, a lot of attention has been focused on the development and fabrication of suitable nanocarriers for improved and sustained drug delivery in the pulmonary system. Nanoparticle-based therapeutic modality has been evaluated in in-vitro and ex-vivo silicosis models for prolongation of drug activity and improved therapeutic outcomes. The preclinical findings open the doors to clinical trials for operational and regenerative nanoformulations, which eventually create a positive change in medical practice. The following review summarizes various therapeutic approaches available and in the pipe line for silicosis and also stresses the preventive practices for effectively combating this occupational hazard.

Screening Workers for Occupational Exposure to Respirable Crystalline Silica: Development and Usability of an Electronic Data Capture Tool

Background

Cases of the occupational lung disease silicosis have been identified in workers processing artificial stone in the stone benchtop industry (SBI). In the Australian state of Victoria, the Regulator commissioned a screening program for all workers in this industry.

Objective

To facilitate systematic data collection, including high-quality exposure assessment, an electronic data capture tool (EDCT) was developed.

Methods

A multidisciplinary team developed an EDCT using Research Electronic Data Capture (REDCap; Vanderbilt University). The needs of the EDCT were (1) data entry by multiple clinicians and the workers attending for screening and (2) systematic collection of data for clinical and research purposes. The comprehensibility and utility of the tool were investigated with a sample of workers, and the EDCT was subsequently refined.

Results

The EDCT was used in clinical practice, with capacity for data extraction for research. Testing of comprehension and utility was undertaken with 15 workers, and the refined version of the Occupational Silica Exposure Assessment Tool (OSEAT) was subsequently developed.

Conclusions

The refined OSEAT has been determined to be comprehensible to workers and capable of collecting exposure data suitable for assessment of risk of silicosis. It was developed for workers in the SBI in Australia and is adaptable, including translation into other languages. It can also be modified for SBI workers in other countries and for use by workers from other industries (mining, construction) at risk of silica exposure, including in lower-income settings.

Measuring improvements in occupational health and safety in the artificial stone benchtop industry

OBJECTIVES

Workers in the stone benchtop industry in Australia are at high risk of silicosis due to exposure to respirable crystalline silica (RCS) from the dry processing of artificial stone. In Victoria, Australia, a multifaceted response including education, regulatory changes, inspection site visits, and occupational health screening programme began in 2019. We aimed to review the success of this approach to safety practices in the industry.

METHODS

Data were available from 2 sources: first, responses provided by workers during their occupational health screening (2019 to 2024), which included a systematic occupational history. Jobs examined included roles in the stone benchtop industry with RCS exposure and were analysed in relation to reported safety practices pre and postregulatory changes in August 2019, which prohibited unrestricted dry cutting. Second, data were obtained from the Regulator describing the numbers of visits to industry worksites and the numbers and types of compliance notices issued between 2018 and 2024.

RESULTS

In total, 1921 jobs from 1007 workers were eligible for analysis, of which 869 were prior to the 2019 regulatory change and 557 commenced after. The proportion of workers reporting "never" dry cutting rose from 17.3% to 67.2% (P < 0.001), use of recommended ventilation and respirator increased from 26.0% to 36.5% (P < 0.001), and 44.9% to 86.5% (P < 0.001), respectively. Of the 543 worksites visited (2757 site visits in total), 352 (64.8%) received at least one compliance notice and the types of notices varied over time. Administrative controls/housekeeping and health monitoring notices were the most common in 2019 to 2021 but tools/equipment notices increased substantially in 2022 onwards.

DISCUSSION

Prior to the changes, a large proportion of jobs involved unrestricted dry processing of artificial stone with inadequate protection. After the changes, practices improved although some jobs continued to involve dry processing without adequate control of dust.

CONCLUSIONS

This multifaceted approach vastly improved safety practices in the stone benchtop industry over 5 years. These data are relevant to occupational health and safety professionals and regulators in countries where artificial stone is used and potentially for implementation of new measures in response to a new workplace hazard in future.

From Engineered Stone Slab to Silicosis: A Synthesis of Exposure Science and Medical Evidence

Engineered stone (ES) is a popular building product, due to its architectural versatility and generally lower cost. However, the fabrication of organic resin-based ES kitchen benchtops from slabs has been associated with alarming rates of silicosis among workers. In 2024, fifteen years after the first reported ES-related cases in the world, Australia became the first country to ban the use and importation of ES. A range of interacting factors are relevant for ES-associated silicosis, including ES material composition, characteristics of dust exposure and lung cell-particle response. In turn, these are influenced by consumer demand, work practices, particle size and chemistry, dust control measures, industry regulation and worker-related characteristics. This literature review provides an evidence synthesis using a narrative approach, with the themes of product, exposure and host. Exposure pathways and pathogenesis are explored. Apart from crystalline silica content, consideration is given to non-siliceous ES components such as resins and metals that may modify chemical interactions and disease risk. Preventive effort can be aligned with each theme and associated evidence.

Nano-enabled delivery of diosgenin and emodin ameliorates respirable silica dust-induced pulmonary fibrosis silicosis in rats

Oxidative stress and inflammation play a fundamental role in the beginning and advancement of silicosis. Hence, questing active phytocompounds (APCs) with anti-oxidative and anti-inflammatory properties such as diosgenin (DG) and emodin (ED) can be a therapeutic intervention targeting silica-induced pulmonary inflammation and fibrosis. Hydrophobicity and low bioavailability are the barriers that restrict the therapeutic efficacy of DG and ED against pulmonary defects. Encapsulating these APCs in polymeric nanoparticles can overcome this limitation. The present study has thus explored the anti-inflammatory and anti-fibrotic effects of polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) individually loaded with DG (DGn) or ED (EDn) and in combine DG+ED [(DG+ED)n] in respirable silica dust (RSD)-induced pulmonary fibrosis silicosis rat model. Our study found that individual and combined NPs revealed physiochemical characteristics appropriate for IV administration with sustained-drug release purposes. Physiological evaluations of RSD-induced silicosis rats suggested that no treatment could improve the body weight. Still, they reduced the lung coefficient by maintaining lung moisture. Only (DG+ED)n significantly cleared free lung silica. All interventions were found to attribute the increased per cent cell viability in BALF, reduce cytotoxicity via minimizing LDH levels, and balance the oxidant-antioxidant status in silicotic rats. The expression of inflammatory cytokines (TNF-α, IL-1β, IL-6, MCP-1, and TGF-β1) were efficiently down-regulated with NPs interventions compared to pure (DG+ED) treatment. All drug treatments significantly declined, the 8-HdG and HYP productions indicate that RSD-induced oxidative DNA damage and collagen deposition were successfully repaired. Moreover, histopathological investigations proposed that individual or combined drugs NPs interventions could decrease the fibrosis and alveolitis grades in RSD-induced silicosis rats. However, (DG+ED)n intervention significantly inhibited pulmonary fibrosis and alveolitis compared to pure (DG+ED) treatment. In conclusion, the RSD can induce oxidative stress and inflammation in rats, producing reactive oxygen species (ROS)-mediated cytotoxicity to pulmonary cells and leading to silicosis development. The IV administration of combined NP suppressed lung inflammation and collagen formation by maintaining oxidant-antioxidant status and effectively interrupting the fibrosis-silicosis progression. These results may be attributed to the improved bioavailability of DG and ED through their combined nano-encapsulation-mediated targeted drug delivery.

Psychometric properties of the Perceived Stress Scale (PSS-10) in silica-exposed workers from diverse cultural and linguistic backgrounds

BACKGROUND

The Perceived Stress Scale (PSS-10) has been used in a range of occupational cohorts, but only recently in stone benchtop workers undergoing screening for silicosis. The aim of this study was to compare psychometric properties of the PSS-10 in stone benchtop workers amongst those born overseas or who used an interpreter.

METHODS

Stone benchtop workers in Melbourne, Australia completed the PSS-10 as part of their occupational screening for silicosis. Internal consistency was assessed with Cronbach's α for the total score and the positive and negative subscales. Validity was assessed using confirmatory factor analysis (CFA). Analysis was performed for the total group and for subgroups according to sex, interpreter use, overseas-born, and language spoken at home.

RESULTS

The results of 682 workers with complete PSS-10 scores were included in analysis. Most participants were male (93%), with mean age 36.9 years (SD 11.4), with just over half (51.6%) born in Australia, 10.1% using an interpreter, and 17.5% using a language other than English at home. Cronbach's α for the overall group (α = 0.878) suggested good internal consistency.

DISCUSSION

CFA analysis for validity testing suggested PSS-10 performance was good for both sexes, moderate for country of birth and language spoken at home categories, but poorer for those who used an interpreter. Whilst professional interpreters provide a range of benefits in the clinical setting, the use of translated and validated instruments are important, particularly in cohorts with large numbers of migrant workers.

CONCLUSION

This study describes the psychometric properties of the PSS-10 in a population of stone benchtop workers, with good internal consistency, and mixed performance from validity testing across various subgroups.

Common and distinct risk factors that influence more severe and distressing shortness of breath profiles in oncology outpatients

BACKGROUND

Shortness of breath occurs in 10%-70% of oncology patients. Very little is known about interindividual variability in its severity and distress and associated risk factors. Using latent profile analyses (LPAs), purpose was to identify subgroups of patients with distinct severity and distress profiles for shortness of breath as single symptom dimensions. In addition, a joint LPA was done using patients' severity AND distress ratings. For each of the three LPAs, differences among the shortness of breath classes in demographic, clinical, symptom, stress, and resilience characteristics were evaluated.

METHODS

Patients completed ratings of severity and distress from shortness of breath a total of six times over two cycles of chemotherapy. All of the other measures were completed at enrollment (i.e., prior to the second or third cycle of chemotherapy). Separate LPAs were done using ratings of severity and distress, as well as a joint analysis using severity AND distress ratings. Differences among the latent classes were evaluated using parametric and nonparametric tests.

RESULTS

For severity, two classes were identified (Slight to Moderate [91.6%] and Moderate to Severe [8.4%]). For distress, two classes were identified (A Little Bit to Somewhat [83.9%] and Somewhat to Quite a Bit [16.1%]). For the joint LPA, two classes were identified (Lower Severity and Distress [79.9%] and Higher Severity and Distress [20.1%]). While distinct risk factors were associated with each of the LPAs, across the three LPAs, the common risk factors associated with membership in the worse class included: a past or current history of smoking, poorer functional status, and higher comorbidity burden. In addition, these patients had a higher symptom burden and higher levels of cancer-specific stress.

CONCLUSIONS

Clinicians can use the information provided in this study to identify high-risk patients and develop individualized interventions.

Interstitial Lung Disease and Sarcoidosis

Interstitial lung disease (ILD), a clinically recognized group of diseases resulting in pulmonary fibrosis, affects up to 200 individuals per 100,000 in the United States. Sarcoidosis has a wide range of clinical manifestations including pulmonary fibrosis. Health disparities are prevalent in both ILD and sarcoidosis around socioeconomic status, race, gender, and geographic location. This review outlines the known health disparities, discusses possible determinants of disparities, and outlines a path to achieve equity in ILD and sarcoidosis.