Characterisation of dust emissions from machined engineered stones to understand the hazard for accelerated silicosis

Chandnee Ramkissoon,Tony Hall,Richard Gun,Shelley Rowett,Sharyn Gaskin,Leigh Thredgold

doi:10.1038/s41598-022-08378-8

Chandnee Ramkissoon, Tony Hall + Show 4 more

Open Access

https://doi.org/10.1038/s41598-022-08378-8

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Abstract

Engineered stones are novel construction materials associated with a recent upsurge in silicosis cases among workers in the stonemason industry. In order to understand the hazard for the short latency of lung disease among stonemasons, we simulated real-time dust exposure scenario by dry-machining engineered stones in controlled conditions, capturing and analysing the respirable dust generated for physical and chemical characteristics. Natural granite and marble were included for comparison. Cutting engineered stones generated high concentrations of very fine particles (< 1 µm) with > 80% respirable crystalline silica content, in the form of quartz and cristobalite. Engineered stones also contained 8–20% resin and 1–8% by weight metal elements. In comparison, natural stones had far lower respirable crystalline silica (4- 30%) and much higher metal content, 29–37%. Natural stone dust emissions also had a smaller surface area than engineered stone, as well as lower surface charge. This study highlighted the physical and chemical variability within engineered stone types as well as between engineered and natural stones. This information will ultimately help understand the unique hazard posed by engineered stone fabrication work and help guide the development of specific engineering control measures targeting lower exposure to respirable crystalline silica.

Highlights

Engineered stones are novel construction materials associated with a recent upsurge in silicosis cases among workers in the stonemason industry
This study has focused on the characterisation of respirable dust following real-time generation from machined engineered stones, representing the most likely scenario facing workers in the engineered stone industry
The importance of analysing freshly-generated engineered respirable silica dust is apparent from the findings of Vallyathan et al.[20], who demonstrated greater free radicals-induced oxidative damage potential from fresh milled quartz compared with aged quartz

Summary

Introduction

Engineered stones are novel construction materials associated with a recent upsurge in silicosis cases among workers in the stonemason industry. Silicosis is an occupational lung disease commonly found in industries such as construction, metallurgy and coal and metal mining/quarrying It is caused by the inhalation of respirable crystalline silica (RCS), in the form of quartz, tridymite or c ristobalite[1]. Engineered stones, referred to as artificial stones, are novel construction materials commonly used for the fabrication of kitchen and bathroom countertops, floor and façade tiles They owe their popularity to their durability, aesthetic appeal, variability and affordability. Marble and granite are two such natural stones containing 3% and 40% silica, respectively Fabrication processes such as cutting, drilling and polishing of engineered stones may result in high atmospheric concentrations of quartz-containing d ust[10]. Finishing tasks often end up being manual without water suppression, resulting in high potential for exposure to crystalline s ilica[11]

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