Silica: The next asbestos?

Silicon dioxide, also known as silica, is a naturally occurring substance that can be found in minerals such as stone. Silica can exist either in a crystalline form such as quartz, or in an amorphous form as found in glass.

Exposure to either can cause ill health effects, however crystalline silica is considered the more harmful. There are different amounts of crystalline silica in different materials, with sandstone generally having a higher concentration of crystalline silica for example than limestone or chalk. 

When crystalline silica is worked, such as when it is cut or grinded, this can produce fine particles of respirable crystalline silica (RCS) dust that can be breathed in by the worker. These dust particles are not visible to the naked eye and it is possible for high concentrations to be inhaled without the worker being aware of this.

People who work in construction, stone masonry or mining and sand blasting, are particularly at risk of inhaling RCS.

After many years of inhaling RCS, or where short but extremely high exposures occur, this can cause silicosis, an occupational lung disease which leaves scarring inside a person’s lungs. Another word for scarring used by doctors is fibrosis. Prolonged exposure to RCS has been associated with other health effects such as lung cancer and COPD. Exposed workers are also at an increased risk of developing tuberculosis (TB), kidney disease and arthritis.

Often, when people suffer from symptoms such as a cough or shortness of breath they associate these symptoms with other health problems. However, if workers have been exposed to RCS at work, this may account for their symptoms and should be considered.

If exposure to RCS is avoided, or sufficiently controlled, then people will not develop silicosis or other completely preventable ill health effects resulting from exposure to RCS.

The scale of the problem

In 2020 the All-Party Parliamentary Group for Respiratory Health (APPG) launched a report on RCS commenting that it could be the next asbestos. 

Asbestos is now known to be a dangerous material and it was used in an unsafe manner for many years. 

As a lawyer specialising in workplace illnesses including asbestos-related diseases, I know all too well the impact exposure to it can have on individuals and their families, often decades after initial contact occurred. Now, around 2,700 people per year are diagnosed with mesothelioma, a form of cancer.

After being delayed by the Covid19 pandemic, the APPG published an updated report on improving silicosis outcomes in the UK in January 2023 after reviewing evidence from clinicians and industry bodies.

According to the APPG:-

• Around 1.36 million people are employed in the construction industry, with 850,000 classed as self-employed;
• There are 1.2 million people in the UK living with COPD;
• It's thought that around 20% of COPD cases may be associated with workplace causes including exposure to RCS;
• There are around 2,000 to 4,000 new cases of interstitial lung disease being diagnosed per year of which a proportion will be due to silicosis
• An estimated 600,000 workers are exposed to silica in the UK each year.

RCS exposure may be causing around 900 new cases of lung cancer each year in Britain.

Tina Conroy, a chartered occupational hygienist from Pragma and Associates, said: “In reality, the extent of exposure to RCS in occupations such as construction, stone masonry, quarrying and manufacturing is most likely to be significantly under reported in the UK with hundreds, if not thousands, of people being affected by ill health because of exposures to RCS. However, all lung disease caused by exposures to RCS is 100% preventable. For change to occur in respect of controlling exposures, it is important to generate better awareness in both those responsible for the work, and those doing the work, about the risks of exposure to RCS. Once people understand the risks, exposures can be controlled, in many cases using relatively simple, already existing solutions. Every worker should be entitled to work in a safe environment and return back to their families reassured that they won’t develop life-changing and often fatal lung diseases, because of exposure to RCS in their work."

The true scale of the problem is probably hidden for a number of reasons:-

• People who work in industries which are likely to have RCS exposure can be self-employed, contractors, or work for small employers.
• There is a lack of understanding and education about what RCS is and how exposure can occur,
• It often takes a long time for RCS exposure to result in someone developing Silicosis.
• Silicosis can be hard for doctors to diagnose because the symptoms of Silicosis are similar to the symptoms of other lung diseases which are considered first.

The APPG also commented that:-

• Silicosis should be a notifiable disease;
• RCS exposure should be recorded by GPs to help with future diagnoses;
• Doctors should take detailed occupational histories when work-related ill health is suspected;
• Occupational health surveillance plays an important role but uptake is frustrated because many workers are self-employed, or employed by small businesses.

It was also felt that there was an under awareness about the dangers posed by exposure to RCS. A common theme from those responding to the APPG was that a programme of education and awareness was essential.

The No Time To Lose Campaign (initiated by IOSH) and the Breathe Freely in Construction Campaign (initiated by the BOHS) are prime examples of targeted industry specific advice available to warn people about the risks of working with RCS.

What can be done?

Whatever the scale of the problem posed by silicosis and other silica related lung disease, it is a preventable health problem. Reducing the numbers of people exposed to RCS will reduce the number of people with a lung disease, and this will reduce the burden of lung diseases on the NHS.

There are legal limits on how much RCS is allowed in the air over a working day. In England, the workplace exposure limit is 0.1 mg/m3 averaged over eight hours. This limit is controversial, with some industry groups calling for the limit to be reduced. For example, the limit in Ireland and Italy is half that of England – 0.05 mg/m3. The APPG recommended that the HSE investigate whether to reduce the work place exposure limit. Notwithstanding this, in the UK there is an additional requirement for employers to reduce exposures to RCS to a level as low as reasonably practicable below the WEL.

Usually, an occupational hygienist needs to sample RCS exposure over a working day. Samples are then sent to a laboratory to be analysed. This means there is often delay getting results on levels of exposure. The APPG were excited by new technology allowing for real time measurements of RCS, because this would allow people at work to change practices and reduce exposure while it was ongoing; however, more work is required to understand whether these technologies are suitable and how best to use these techniques to better understand exposures. Until such techniques can be proven, the APPG recommended the consideration of the HSE published guidance with real time monitors being used to support this.

Unfortunately all too often I see the impact silicosis has on clients. A civil claim for compensation can help patients deal with their condition by securing access to funds to help pay for their care needs or any adaptations to their lives needed as a result of their diagnosis. Unfortunately, a claim cannot take away the injury, and I support any measures to help reduce exposure to RCS, which could potentially be the new asbestos.

Find out more about Irwin Mitchell’s expertise in helping people with silicosis at our dedicated section on the website.