Silicosis — the next asbestos?
Silica is a naturally occurring substance found in rocks, sand and clay. It forms a large constituent element of common construction materials.
From Lancet editorials (“The World is failing on silicosis”) to the publication of the All Party Parliamentary Group on Respiratory Disease on the 4 March 2020, concern is growing that silicosis may resemble the next asbestos.
In this article, we summarise the main risks to health, seek to understand how widespread occupational exposure has and continues to be and how this may translate into future claims.
What is silica?
Silica is a naturally occurring substance found in rocks, sand and clay. It forms a large constituent element of common construction materials — bricks, tiles, concrete and mortar. Sandstone as an example has a silica content of approaching 70%.
What are the health risks?
Silicosis is the most well-known lung condition associated with the inhalation of respirable silica dust. In brief, this is a progressive lung condition that usually only develops after many years of exposure to respirable silica dust.
Latency shortens if exposure is more intense or the exposure is to materials with a higher silica content. It presents clinically with nodular lesions leading to lung fibrosis.
Respirable crystalline silica exposure is also associated with Chronic Obstructive Pulmonary Disease (COPD) — a group of lung conditions that include bronchitis and emphysema both in terms of triggering or exacerbating underlying conditions.
The synergistic impact of smoking and silica exposure is not clearly defined. Some studies, notably; Brown “Silica exposure, smoking, silicosis and lung cancer” (Occupational Medicine, 2009), suggest silica exposure and smoking act together to increase the risk of lung cancer. In other studies, a synergistic impact is less clear.
Respiratory disability increases over time — combining with naturally occurring reduced lung function caused by the body's decline in age. Other than monitoring pulmonary function, the administration of oxygen and ultimately lung transplantation, there is little by way of active treatment.
Historical occupational exposure
Silicosis as a disease is historically associated with the steelworks and foundries traditionally based in the North and Midlands. Silica sand formed an integral part of the manufacturing process where exposure was due to the fettling or cleaning of products.
It is also historically associated with mining and quarrying operations where rock and minerals are cut or ground to size and shape.
Whilst the decline of these traditional industries which began from the mid-1970s onwards had led to a decline in silicosis cases, recent concern has centred around both exposure within the construction industry and the increasing use of artificial stone.
The construction industry - the latest research
Following a consultation which concluded in July 2019, the All Party Parliamentary Committee on respiratory diseases working in association with the not for profit organisation B and CE published its report on 4 March 2020.
The main findings and recommendations were;
600,000 UK workers were exposed to silica dust each year.
Workplace exposure limits should be reduced from the present 0.1 mg/m3 to 0.05 mg/m3.
An awareness campaign should be launched.
Occupational services should be allowed into GP surgeries to allow accurate work histories to be taken.
New regulations should be introduced to bring silica in line with asbestos.
Artificial stone and silicosis
The growth in the use of artificial stone in the kitchen and bathroom worktops is a trend seen over the last decade.
As manufacturing, finishing and installation of artificial stone countertops have increased over the last 15 years, its impact on silicosis rates is starting to be felt worldwide.
Artificial stone commonly has a very high silica content — commonly 90%, which compared to marble — 3% or granite — 30%. Consequently, if respiratory protective equipment is either not worn or is inadequate, even relatively short periods of exposure may cause silicosis/COPD to develop.
A number of recent studies have considered the health risks.
- “Artificial stone associated silicosis — a rapidly emerging lung disease”
[Occupational and Environmental Medicine, January 2018].
- Rose et al [September 2019];
This was a US study that reported 18 cases across two factories of employees working with engineered stone. It reported that quartz surface imports had increased by 800 % between 2010 and 2018.
- A study by Leso and others;
“Artificial stone associated silicosis — a systematic review
[Journal of Environmental and Public Health, February 2019]
This concentrated on a review of eight main worldwide studies in demonstrating a causal relationship between unprotected exposure to artificial stone and silicosis.
The authors report, “unusually high incidence of disease reported over short period of exposure”.
The current COVID-19 pandemic will undoubtedly mean that the All Party Parliamentary Committees ‘call for arms’ is likely to be paused for a number of months.
As and when normality returns, both awareness campaigns and wider recommendations are likely to receive governmental and HSE focus.
Both are likely to result in an uptick in both diagnosis and claims, particularly if more detailed occupational histories are taken. Whilst this may fall heavily on legacy insurers, current and more recent insurers transacting employers liability business will not be immune.
Ensuring that those engaged in the construction industry and particularly those manufacturing, installing or cutting artificial stone are complying with current COSHH Regulations and workplace exposure limits will be key to avoiding ‘another asbestos’.