An old threat in a new setting: High prevalence of silicosis among jewelry workers

Biomarkers related to silicosis and pulmonary function in individuals exposed to silica

BACKGROUND

The identification of markers that can facilitate the early diagnosis of silicosis has remained challenging. We evaluated the association of inflammatory markers with the presence of silicosis and lung function impairment in individuals exposed to silica.

METHODS

Individuals exposed and not exposed to silica were assessed by occupational history, clinical findings, lung function, chest imaging findings, and inflammatory markers.

RESULTS

Among 297 men evaluated, 51 were unexposed controls (G1), 149 were exposed to silica without silicosis (G2), and 97 were exposed to silica with silicosis (G3). Inflammatory marker levels were higher in G3 than in G2 and G1. Platelet/lymphocyte ratio (PLR), lactate dehydrogenase (LDH), soluble tumor necrosis factor II (sTNFRII), and macrophage inflammatory protein-4 (MIP-4) were associated with silicosis, and LDH, neutrophil/lymphocyte ratio (NLR), sTNFRII, monocyte chemoattractant protein-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and fibrinogen were negatively associated with lung function.

CONCLUSION

Blood inflammatory markers are associated with silicosis and impaired lung function.

P2Y12 Receptor Antagonist Clopidogrel Attenuates Lung Inflammation Triggered by Silica Particles

Silicosis is an occupational lung disease caused by inhalation of silica particles. It is characterized by intense lung inflammation, with progressive and irreversible fibrosis, leading to impaired lung function. Purinergic signaling modulates silica-induced lung inflammation and fibrosis through P2X7 receptor. In the present study, we investigate the role of P2Y12, the G-protein-coupled subfamily prototype of P2 receptor class in silicosis. To that end, BALB/c mice received an intratracheal injection of PBS or silica particles (20 mg), without or with P2Y12 receptor blockade by clopidogrel (20 mg/kg body weight by gavage every 48 h) - groups CTRL, SIL, and SIL + Clopi, respectively. After 14 days, lung mechanics were determined by the end-inflation occlusion method. Lung histology was analyzed, and lung parenchyma production of nitric oxide and cytokines (IL-1β, IL-6, TNF-α, and TGF-β) were determined. Silica injection reduced animal survival and increased all lung mechanical parameters in relation to CTRL, followed by diffuse lung parenchyma inflammation, increased neutrophil infiltration, collagen deposition and increased pro-inflammatory and pro-fibrogenic cytokine secretion, as well as increased nitrite production. Clopidogrel treatment prevented silica-induced changes in lung function, and significantly reduced lung inflammation, fibrosis, as well as cytokine and nitrite production. These data suggest that inhibition of P2Y12 signaling improves silica-induced lung inflammation, preventing lung functional changes and mortality. Our results corroborate previous observations of silica-induced lung changes and expand the understanding of purinergic signaling in this process.

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.

Evaluation of workplace exposure to respirable crystalline silica in Italy

BACKGROUND

Crystalline silica is a human carcinogen and its use is widespread among construction, mining, foundries, and other manufacturing industries.

PURPOSE

To evaluate occupational exposure to crystalline silica in Italy.

METHODS

Data were collected from exposure registries and descriptive statistics were calculated for exposure-related variables. The number of potentially exposed workers was estimated in a subset of industrial sectors. Linear mixed model analysis was performed to determine factors affecting the exposure level.

RESULTS

We found 1387 cases of crystalline silica exposure between 1996 and 2012. Exposure was most common in construction work (AM = 0·057 mg/m(3), N = 505), and among miners and quarry workers (AM = 0·048 mg/m(3), N = 238). We estimated that 41 643 workers were at risk of exposure in the selected industrial sectors during the same period.

CONCLUSIONS

This study identified high-risk sectors for occupational exposure to crystalline silica, which can help guide targeted dust control interventions and health promotion campaigns in the workplace.

Assessment of the lung function status of the goldsmiths working in an unorganized sector of India

Context:

Exposure to various types of fumes and gases are very common in Jewelery industries. No Report is available regarding the effects of those fumes and gases on the respiratory functions of the goldsmiths. Due to lack of proper monitoring of the workplace environments in these unorganized sectors, workers get very much affected by the occupational exposures to those irritants.

Aims:

The present study aimed to investigate whether the occupational exposures to fumes and gases might alter the lung functions of the goldsmiths.

Materials and Methods:

A total of 118 goldsmiths and 66 unexposed control subjects were taken randomly for the study. The goldsmiths were further classified in 3 groups according to duration (year) of exposures in the work environment, ETA₁ (less than 5 years), ETA₂ (more than 5 years but less than 10 years), and ETA₃ (more than 10 years). Peak expiratory flow rates (PEFR), forced vital capacity (FVC), and forced expiratory flow rates of different intervals (FEF_25%, FEF_50%, FEF_75%, FEF_25-75%) were measured using computerized Spirometer (Maestros Mediline, India). The statistical analyses were carried out using Minitab software version 3.

Results:

Lung functions of the goldsmiths significantly (P < 0.01) decreased from that of the control group. Inter-group comparison also showed the deteriorations of lung functions was associated with exposure time, and more exposed workers had significantly less (P < 0.01) efficiencies of lung functions.

Conclusions:

Workplace fumes and gases were responsible for deterioration of the lung function status of the goldsmiths.

The burden of exposure-related diffuse lung disease

Estimating the burden of exposure-related diffuse lung disease in terms of health effects and economic burden remains challenging. Labor statistics are inadequate to define the scope of the problem, and few studies have analyzed the prevalence of exposure-related illnesses and the subsequent health care cost. Well-defined exposures, such as those associated with coal mines, asbestos mines, and stonecutting, have led to more accurate assessment of prevalence and cost. As governmental regulation of workplace exposure has increased, the prevalence of diseases such as silicosis and coal workers' pneumoconiosis has diminished. However, the health and economic effects of diseases with long latency periods, such as asbestosis and mesothelioma, continue to increase in the short term. Newer exposures, such as those related to air pollution, nylon flock, and the World Trade Center collapse, have added to these costs. As a result, estimates of cost for occupational diseases, including respiratory illnesses, exceed $26 billion annually, and the true economic burden is likely much higher.

Occupational exposure to crystalline silica: estimating the number of workers potentially at high risk in Italy

BACKGROUND

Occupational exposure to free silica is widespread in several economic sectors and is well known to cause silicosis. This study was designed to establish a database of enterprises and workers in industrial sectors involving silica exposure in Italy and to estimate the number of workers potentially at high risk of exposure.

METHODS

The industrial sectors at risk of silica exposure were identified by selecting the industrial sector that employed people who were compensated for silicosis in 2000-2004. The enterprises and the number of workers (blue-collar) potentially at risk of silica exposure were selected from the Italian database of workplaces.

RESULTS

The number of workers potentially at high risk of silica exposure, were 28,712. The most involved sectors were: construction, mining and quarrying, metal working, and manufacturing of non-metallic products. Among regions in Italy, some exposure-disease scenarios were cited in literature, particularly in Sardinia, Liguria, and Tuscany.

CONCLUSIONS

Establishing a database of industries related to silica dust exposure and identifying the number of workers potentially at high risk can be useful to reinforce preventive measures and to control exposure.