In the October 2024 edition of Thorax a short case study was presented which set out the first 8 medically reported cases of silicosis due to artificial stone (AS) in the UK.

Below are some of the key findings of the study, highlighting issues which may be of interest to occupational disease layers.

(Artificial stone silicosis: a UK case series. Johanna Feary, Anand Devaraj, Matthew Burton, Felix Chua, Robina K Coker, Arnab Datta, Richard J Hewitt, Maria Kokosi, Vaslis Kouranos, Carl Jonathan Reynolds, Clare L Ross, Veronica Smith, Katie Ward, Melissa Wickremasinghe, Joanna Szram)

Introduction

There has been a rapid increase in use of artificial stone in the UK in the last 2 decades, used in the manufacture of stone worktops. While traditional silicosis has long been recognised as an occupational disease, the rise of such engineered stone worktops has introduced a new and more aggressive form of the disease.

The Rise of Artificial Stone and Its Hidden Dangers

Artificial stone - also known as reconstituted or engineered quartz - is a composite material made from crushed stone bound with resins and pigments. AS has advantages as to durability and ease of manufacture over natural stone. However, it contains over 90% crystalline silica, far exceeding the silica content found in, for example, granite (30%) or marble (3%).

Workers cutting and polishing AS are exposed to respirable crystalline silica (RCS), which, without proper protection, leads to a particularly aggressive form of silicosis owing to 3 factors: the high silica content; the very fine particles formed when cut; and that preparation is frequently ‘dry’ cut using angle grinders and other hand tools, without water suppression.

Accordingly, the AS disease manifests more quickly than traditional silicosis, with cases emerging after as little as four years of exposure, rather than the decades traditionally associated with the condition.

The UK’s First Confirmed Cases

This case series identified eight confirmed instances of AS silicosis in young men, with a median age of 34 years. 75% had been born outside the UK. They had all been employed by small businesses (fewer than 10 employees).

None were involved with the manufacture of the worktops but rather finishing processes such as cutting and polishing. 

Alarmingly, these cases closely mirror those already reported in Australia, Spain, the USA, and Israel, where AS silicosis has surged.

The key clinical findings include:

• Rapid disease onset with median exposure of 12.5 years, but some cases developing in as little as 4 - 8 years.
• Symptoms often misdiagnosed as sarcoidosis due to similar radiological features.
• Severe disease progression, with three workers requiring lung transplants and one fatality already recorded.
• Elevated autoimmune markers and evidence of systemic effects beyond the lungs.

Preventative Measures

None of the workers described any water suppression measures. All reported inadequate respiratory protection. Ventilation, if present, was not regularly cleaned/ serviced. There was no knowledge of any workplace dust monitoring.

It is reported that none of the cases were under RCS health surveillance.

It is noted, though, that HSE in 2016 published guidance as to medical surveillance for workers exposed to RCS, including X-ray screening after 15 years of exposure. However, given the short latency in these cases, such surveillance would have failed to detect problems in at least some of these reported cases.

There is one particularly notable line of the article as to typical AS workplaces:

“The AS market is dominated by small companies in which regulation has been shown to be challenging to implement”.

Conclusion

These medically reported cases of AS silicosis show the increased dangers of working with AS over natural stone. 

Safety measures which consider intensity of exposure as well as duration are recommended.

In Australia, AS has now been banned due to its severe health risks.

The authors recommend national guidelines to identify the at-risk population and reduce risks, and prevent the ‘epidemic’ seen in other countries.