Identification of early-stage silicosis through health screening of stone benchtop industry workers in Victoria, Australia

Abstract

ObjectivesThe popularity of high silica content artificial stone has been associated with emergence of severe, progressive silicosis as a major health issue affecting workers in the stone benchtop industry. This population-based health assessment programme has been implemented with the aim of identifcation of silica-associated disease at a preclinical stage.MethodsAll current and former workers from the stone benchtop industry in the State of Victoria are offered free health assessments. Primary evaluations include a standardised questionnaire, physical examination, spirometry and gas transfer assessment and International Labour Organisation-categorised chest X-ray. Secondary evaluations include high-resolution CT chest, blood tests and a respiratory physician evaluation.ResultsAt the end of the first 12 months, 86/239 (36%) workers who had completed secondary evaluation were diagnosed with silicosis (65 simple silicosis and 21 complicated silicosis). 22 had worked in the industry for less than 10 years at the time of diagnosis. Of those with simple silicosis, 80% of workers reported breathlessness only with strenuous exercise (modified Medical Research Council score of 0), and lung function was well preserved (prebronchodilator forced vital capacity mean 99.8% predicted (SD 13.6), diffusion capacity of the lung for carbon monoxide mean 96.2% predicted (SD 18.0)). Antinuclear antibodies were detected in 37% with silicosis and 24% without silicosis.ConclusionEarly results from this comprehensive health assessment programme have indicated a high proportion of referred artificial stone benchtop workers have silicosis, including many with early-stage disease. The common finding of antinuclear antibodies suggest significant potential for autoimmune disease in this occupational group.

Compositional and structural analysis of engineered stones and inorganic particles in silicotic nodules of exposed workers

“…This suspicion is reinforced by some studies; screening in ES workers in California has shown that 12% suffer from silicosis, diagnosed by chest radiology and ILO classification [ 52 ]. In addition, a more exhaustive evaluation in workers in Victoria (Australia) using chest radiology and HRCT showed that the percentage of patients with silicosis increased to 36% because HRCT detected cases with negative chest radiology [ 53 ]. If we consider that the number of exposed workers in the US is close to 100,000, we will have an idea of the magnitude of the problem.…”

Silica Exposure Estimates in Artificial Stone Benchtop Fabrication and Adverse Respiratory Outcomes

“…Those identified as ‘at risk of silicosis’ were referred to a respiratory physician for further evaluation including a high-resolution computed tomography (HRCT) chest scan. More details of the questionnaire and RHS methods are provided in an earlier paper ( Hoy et al , 2020 ).…”

“…WorkSafe Victoria (WSV) funded respiratory health screening (RHS) for all past and present workers in benchtop fabrication businesses. Some preliminary silicosis findings from the first year of the registry have been published ( Hoy et al , 2020 ). This paper extends the earlier paper by looking at a larger group of workers.…”

Exposure to respirable dust among workers fabricating aluminium trihydroxide-containing synthetic countertops

“…Exposure simulations indicate that working with ATH-containing synthetic countertops can lead to substantial airborne dust. In one set of simulated exposures, dust generated from cutting Corian™ was 32% in the respirable size range, contained 82% aluminium hydroxide, and had a respirable mass concentration as high as 1.52 mg/m 3 3 , 7 . A subsequent report using a similar simulated approach found that nearly twice as much of the dust produced (59%) was in the respirable range 8 .…”