Abstract

Objective: Cases of artificial stone (AS) silicosis caused by inhalation of respirable crystalline silica dust derived from engineered or artificial stone primarily used in kitchen and bathroom worktops have risen in the last 15 years. This presentation will summarise the global epidemiology of AS silicosis.

Methods: A literature search was carried out and the findings summarised including data on incidence of AS silicosis, demographics, occupational exposures and clinical outcomes.

Results: Since first reported in 2010 in Spain, the incidence of AS silicosis has increased rapidly with case series now published from Italy, Israel, Australia, USA, China, Belgium and the UK. The size of the exposed workforce is estimated to be over 100,000 in the USA alone. Over 1000 cases have been reported globally but are likely underestimated with large-scale screening programmes using CT scans identifying a prevalence of up to 28% in exposed workers in Australia. In each country both the epidemic curve and the clinical pictures are strikingly similar. Typically, it affects young male workers in their 30s and 40s working in worktop fabrication and installation roles and who are often migrant workers. Compared with silicosis from natural stone, AS silicosis is associated with a high prevalence of acute and accelerated disease, disease progression to progressive massive fibrosis and need for lung transplant. Key risk factors include dry cutting, inadequate ventilation and inappropriate or no respiratory protection. Emerging clusters have also been linked to small-scale, informal workshops lacking regulatory oversight.

Conclusion: AS silicosis is a preventable occupational health crisis and cases are likely to continue to rise globally. Under-recognition and under-reporting of cases is likely to be high. Urgent action is required to reduce workers’ exposures and implement comprehensive screening programs to reduce disease burden and prevent further cases.

Christina Dimitriadis, Jessy Hansen, Ryan F. Hoy, Fiona Hore-Lacy, Malcolm R. Sim

Abstract

This exposure assessment was in support of the Artificial Stone worker screening program funded by the Victorian Regulator. The major determinants of RCS exposure were likely to be the proportion of time working on AS, the proportion of time dry processing. For each job, the participants were asked to estimate the proportion of time spent doing dry work and the proportion of time spent near someone else doing dry work for each job and the proportion of work on AS vs natural stone. These parameters were used to derive intensity of exposure to RCS which was used to weight duration of exposure. The ventilation and RPE were not included in the exposure metric. The values used to weight the exposure estimate by intensity of exposure were chosen a priori. We used a 10-fold weighting for dry versus wet work (HSE 2001). Data from four workplaces where granite was being cut showed that changing from dry to wet cutting reduced 8-h TWA exposure by approximately an order of magnitude (Simcox et al., 1999). A similar 10-fold reduction in exposure was seen between wet and dry cutting of AS (Cooper et al., 2015). A weighting factor of 0.3 was used to account for the difference between all natural stone and all AS work. AS typically contains over 90% silica content compared to granite with 30% silica and marble of about 2% silica. The job intensity correlated well with the reported jobs e.g. installer vs machinist vs CNC machine operator. This led to the development of a decision tree grouping workers by specific job types. For individuals, weighted cumulative exposure was calculated by multiplying job exposure intensity values by duration for each job and then adding together the results of all jobs. Averaged exposure intensity was calculated the weighted cumulative exposure by the duration of exposure summed over all reported jobs and this predicted risk of silicosis.

Ruth Wiggans, David Fishwick, George McHale, Laura Byrne, Jo Feary, Marcella Mauro

Abstract

Objective: Many countries have seen cases of silicosis in workers exposed to dust from artificial stone (AS silicosis). Australia banned the use of this material in 2024. However, little is known about the incidence of AS silicosis in other countries and what approaches are adopted to reduce the risk of silicosis in exposed populations.

Methodology: A survey was distributed to occupational and respiratory health professionals in Europe, to collect information on number of AS silicosis cases , health surveillance and policy initiatives.

Results: 62 responses were obtained from 20 countries. Twenty respondents from 7 countries reported that AS silicosis cases have been observed, with the number of cases ranging from 5 to 50-100. Ten respondents have seen patients with AS silicosis. Most reported that health surveillance for silicosis was available, but nearly half claimed that health surveillance was not effective in identifying silicosis cases. Research is being carried out, or is the process of being set up, by 9 respondents, and included epidemiological (cross-sectional, case-control) and exposure studies. Others reported that specific health surveillance or case registries were set up. Over 50% of the respondents believed that a ban should be implemented. Only 3 respondents claimed that a ban was being discussed in their country, although other risk management initiatives risk were reported. Eight respondents reported that high silica content AS was being replaced by lower silica content materials.

Conclusion: Given the widespread use of AS, and likely underdiagnosis of silicosis, it is highly likely the cases of AS silicosis observed to date present only the “tip of the iceberg”, and that a sustained effort is required to determine and reduce the risk of working with these materials. Most of the participants were in favour of a ban of the use of engineered stone for kitchen worktops.