Is silica the biggest health and safety issue of today?

The side effects of prolonged exposure to silica became more widely known in the late eighties, and while progress has been made in increasing safety parameters, the material is still causing thousands of preventable deaths each year across the world.

What is Respirable Silica Dust?

Respirable silica is a form of dust particle that when breathed into our bodies, can penetrate deep into our lungs causing irreversible damage. According to Safe Work Australia, respirable silica is generated through workplace mechanical processes such as crushing, cutting, drilling, grinding, sawing or polishing of natural stone or man-made products that contain silica.

Prolonged exposure to silica dust can lead to silicosis or better yet ‘pneumonoultramicroscopicsilicovolcanoconiosis’. In what is incidentally the longest word in the English language, 45 letters to be exact, it is a rather overt way to describe a covert disease. Ironic.

Symptoms of silicosis can include shortness of breath, chest pain, fatigue, severe cough and in its most extreme form, can lead to the development of lung cancer and pulmonary tuberculosis.

There is no known cure for silicosis: once detected, it is too late. A lung damaged by silicosis will never regain full health. Its impact is so severe, that in 1997, silica was classified as a Group One human carcinogen (, 2019) – the same classification given to other respiratory hazards such as asbestos.

Who is it Affecting?

Silica is present in construction materials such as bricks, concrete, tiles, sandstone and granite. For most people working in the construction, mining, stone works, pottery, manufacturing and sandblasting fields, these materials are a part of day-to-day life.

According to Silicosis and Lung Cancer: Current Perspectives (2018), approximately 23 million workers have been exposed to silica in China alone. In India, this number is halved to around 11.5 million. In the United States and Europe respectively, approximately two million workers have been exposed to silica dust, while in Australia, roughly half a million exposure cases have been reported.

Incidents of silica-related lung disease and death vary from country to country, as regulations and safety procedures are not standardized. In China, it is estimated that 4.2% of exposures to silica have led to or can be linked to deaths, while in Australia, roughly 1% of exposure cases will lead to lung cancer in the future.

Meanwhile in the UK, as recently as July 2019, a parliamentary inquiry was launched to better assess the impact of silicosis on the health and well-being of construction workers, following a spate of deaths. According to the Health and Safety Executive (HSE), there have been up to 20 silicosis-related deaths annually due to lung disease over the last decade. This has not factored in other related illnesses such as tuberculosis and kidney disease. In 2014, HSE labelled silicosis as the second biggest health risk to construction workers after asbestos.

Among the most at-risk industries, construction workers have traditionally been the most exposed to the dangerous airborne substance. However, workers in the mining industry now experience the highest risk of lung cancer due to the magnitude and duration of their silica exposure (2018).

The Imperative for Occupational Health & Safety Controls

 The good news is that silicosis is entirely preventable if we avoid exposure. According to the Australian Institute of Occupational Hygienists (AIOH) and the World Health Organisation (WHO), the hierarchy for preventing exposure is:


Peter Aspinall, Principal Occupational Hygienist for WSP in Australia, acknowledges that if we can prevent silica dust exposure to our workers, the issue becomes irrelevant. He says, “Control of the exposure source is the best point to start when attempting to strategically minimise the hazard. However, the problem exists in the materials that we use to construct even the most basic infrastructure projects. Bricks and mortar have been used for centuries, so completely eradicating these materials from our workplace and home in the short term is unlikely.”

Education is Key

 Recently, we’ve seen significant changes in the health and safety space, including the dramatic shift in the importance of worker health awareness and safety.

 “When it comes to occupational health and hygiene, we want the industry to see the benefits of becoming more proactive rather than reactive – that’s where we can add real value to our clients’ projects,” adds Peter.

 How can we encourage workplaces to be more proactive? From the late eighties through to the mid-nineties there was a major international push to educate the industry around the dangers of respirable silica dust. Much of the research came from the USA, with China, the UK, Canada and South Africa also supporting the cause.

 Peter says, “There are some easy preventative solutions available to curb the onset of silicosis. Engineering and safety in design processes can reduce the need for cutting or drilling into silica materials. What’s more, materials can be installed pre-cut and built offsite to minimise silica generation in the workplace.”

 “Wet-cutting, proper extraction (H Class) ventilation systems and personal respirators are effective, but should not be undertaken without education to control the level of worker exposures. These precautionary steps can and should be taken on all projects no matter their size. When it comes to health safety, all measures should be applied.”

 WSP works with our clients to set comprehensive workplace safety standards on all projects, for the benefit of the communities in which we operate. Essentially, we provide control over all aspects of the project hierarchy from the option to eliminate or provide engineering controls for a source right through to the management of the personal exposures.

“If you look at how far we have come against other respirable hazards such as asbestos, you see what we can achieve with silica dust. We can help reduce the risk and ensure our clients and communities remain safe at all times.”

Controlling Silica

Across the world, WSP is helping our clients manage the safety and exposure risks to its workers.

By identifying and reducing health risks in the workplace, we can help organisations improve employee comfort, well-being and productivity as well as meet our clients’ health and safety obligations.


In Australia, we have assisted in remediating and designing the health and safety compliance programs for some of the largest urban renewal programs in the country. We have also helped small manufacturing business and artisan stone masons with managing direct exposure risks.

In July 2019, the Australian Government Department of Health established a National Dust Disease Taskforce to develop a national approach to the prevention, early identification, control and management of dust diseases. This includes establishing a National Dust Disease Register, and undertaking new research to support understanding, prevention and treatment of occupational lung diseases.

“This coordinated approach to tackling the issue is key to putting a halt to the progression of the disease,” explains Peter.

“Globally, the WHO and the International Labour Organization (ILO) launched a program in 1995 to eliminate it. The only way to protect workers’ health is to control the exposure to silica dust. Many European countries and the USA have shown that preventative measures do work. They require a combination of laws, regulations, exposure limits, technical standards, inspections, reporting and training.”

United Kingdom

In the UK, our team complies with the primary legislation covering exposure to silica dusts – The Control of Substances Hazardous to Health Regulations 2002 (COSHH). This legislation places specific duties on employers to ensure that exposure to all associated substances including silica dusts are controlled under specific conditions.

Ensuring that safety standards are maintained on all projects, our team has looked to a number of initiatives to comply. This includes offsite fabrication to construct concrete slabs for major highway projects such as the A2/M2 and autonomous vehicles testbed. Our Health & Safety team regularly audits contractors to ensure the safest cutting techniques are maintained which include PPE, water suppression systems and extraction vacuums.

North America

In Canada, occupational exposure limits have been established for crystalline silica in most Canadian provinces and territories. Along with provincial regulations, guidance documents within select provinces have been established to provide employers resources to prevent silica exposures through various engineering and administration controls.

Worksafe BC, a statutory agency in the province of British Columbia, along with the British Columbia Construction Safety Alliance, have established a Silica Control Tool™ to aid in the development of an exposure control plan (ECP) for all construction projects. The construction industry has been identified as having the highest exposure to silica according to CAREX , a Canadian national research team for cancerous agents. The Canadian Centre for Occupational Health and Safety (CCOHS) has documented the various preventative measures and resources available to Canadians and Americans to identify and prevent occupational exposures to crystalline silica.

In March 2016, the Occupational Safety and Health Administration (OSHA) issued a crystalline silica standard for the United States construction industry to protect workers from exposure to respirable crystalline silica.

WSP is currently assisting in the remediation and revitalization of Canada’s iconic Massey Hall in Toronto, Ontario. We have investigated and developed plans to mitigate risk to workers to asbestos, silica, and other airborne contaminates.


Respiratory public health is an issue that is increasingly coming to the fore, particularly considering rising densification, infrastructure development and urban air pollution, as demonstrated by this year’s World Environment Day theme – #BeatAirPollution. “It’s time for us to take action, control the hazards, and help our communities thrive,” concludes Peter.

To find out more about Occupational Health and Hygiene and how WSP can help please contact Peter Aspinall or Nathan Redfern.