Silicosis is the oldest occupational lung disease in the world but there is now a surge in cases. Why? And how big is the problem?
In 2012, Ryan Hoy renovated his house and installed an artificial stone benchtop in the middle of his kitchen. Like many Australians, he was sold on its affordability and sleek looks, achieving the same effect as marble or granite at a fraction of the cost.
It wasn’t until years later that Hoy, a respiratory physician, discovered the stone bench contained up to 95 per cent silica, a fine dust that is known to be a leading cause of lung diseases including cancer and silicosis. Although the bench posed no threat to him, he was shocked that the workers who made it were potentially exposed to a dangerous substance.
“I naively assumed that there wouldn’t be such an extraordinarily hazardous material in common use around the country,” says Hoy, a senior research fellow at Monash University’s Centre for Occupational and Environmental Health. “It was mind-boggling to find out just how widespread this has been.” Hoy assumed silicosis was a disease of the past – it is the oldest occupation lung disease in the world – but he is now treating an enormous and growing number of patients with the disease.
The resurgence of silicosis has coincided with a boom in the artificial stone benchtop industry. In November, the building and construction industry union, the CFMMEU, called for a ban on the material, labelling it the asbestos of the 2020s.
So, what is silicosis? How big is the problem? And is silica really the new asbestos?
What is silicosis, and what causes it?
Silicosis is a long-term lung disease caused by inhaling crystalline silica, a fine dust naturally occurring in many construction materials such as stones, rocks, sand, bricks and tiles. Silica is present in particularly large amounts – up to 95 per cent – in engineered stone, the material used to make artificial stone benchtops.
Silica particles are harmless if undisturbed, but can be breathed in once broken up in mining, digging or cutting processes. Inhaling these tiny dust particles can trigger an inflammatory response which, over time, causes small growths called nodules to build up and cluster in the lungs. These make the lungs stiffer, preventing the transfer of oxygen into the blood.
Records of respiratory issues from breathing in dust date back to ancient Greek and Roman times, when miners and stonemasons produced silica dust from cutting and hewing natural materials. Cases peaked in Australia among construction and demolition workers from the 1940s until the ’60s, but increased awareness and better work safety practices helped reduce the prevalence of the disease.
That was until artificial stone benchtops entered the market.
Renee Carey, a Curtin University researcher who has studied the problem of silicosis in the workplace, says it is the large amount of silica dust that is disturbed while manufacturing, cutting and drilling into artificial stone that is of concern to medical and workplace health and safety experts.
“It’s causing silicosis so much quicker than we’re used to, and we’re getting worse silicosis in young workers,” Carey says.
What are the symptoms?
Symptoms can include a cough, shortness of breath and tiredness. There may be no signs in the early stages but the more the disease spreads through the lungs, the more difficult it is to breathe.
Silicosis shares some similarities with asbestosis in that they are both caused by the lung’s reaction to inhaling certain dusts (see below). However, while symptoms from breathing in asbestos do not emerge until decades after the exposure, silicosis can develop in much younger people. Hoy has treated patients in their mid and late 20s. “They get a little bit short of breath when they’re playing with their kids, or maybe work becomes more difficult,” says Hoy.
That can quickly progress to chest pains, fatigue and weight loss as the disease advances. People with silicosis can have trouble sleeping and eating properly, and the disease also increases the risk of other severe conditions such as tuberculosis, lung cancer and emphysema.
How can it be treated?
Despite silicosis being around for a long time, there is still no cure. The damage to the lungs is irreversible, and treatment is mainly about slowing the progression of the disease and relieving its symptoms. Inhalers and oxygen therapy can help improve breathing and quality of life. In severe cases, doctors may recommend a lung transplant.
Researchers in Queensland are trialling a procedure called a whole lung lavage, where a salty solution is pumped into each lung with the aim of “washing out” damaging silica crystals.
Hoy says early screening of workers in the stone benchtop industry has helped identify cases of silicosis before they become symptomatic. If silicosis is spotted early and doctors step in to prevent further exposure, patients may never develop symptoms and lead a normal life.
“There is a proportion of people with silicosis where this is a terrible disease and there’s a high risk of death … but not everybody with silicosis has the same prognosis, and early detection is really key to that.”
Any case of silicosis, Hoy says, is an example of health and safety measures failing to protect workers and should be urgently investigated.
X-rays show the effects of silicosis on victims’ lungs.Credit:Dominic Lorrimer
How big is the problem?
There is no centralised registry for silicosis cases in Australia, so it is difficult to know how widespread the problem is. Carey co-authored research released by Curtin University in 2022 that estimated 584,000 people had been exposed to crystalline silica in 2016. She believes this is an underestimate.
“It was a really simple estimate of how many stonemasons we thought there’d be, based on past research, but we didn’t include people like tunnellers who we know are exposed to silica,” she says. “Pretty much anyone who works in mining or construction, they’re going to be exposed in some way.”
Workers in the stone benchtop industry in Queensland have been regularly screened for silicosis since 2019. Of the 1054 workers monitored so far, 204 have silicosis – a rate of one in five.
In NSW, the Dust Disease Register shows that 10 people died, and 64 people were diagnosed with silicosis in the 12 months to June 2022.
The federal government set up a National Dust Disease Taskforce in 2019 after the death of a 36-year-old stonemason in Queensland. The taskforce (consisting of 10 members including Ryan Hoy) published its final report in June 2021, recommending urgent reforms for the prevention and treatment of silicosis.
It said that if the recommended measures did not improve regulatory compliance rates by 2024 then “immediate action must be taken to ban the product”.
Governments and industry overseas are starting to grapple with silicosis in the worst-offending industries. The Indian government, for example, has a compensation scheme dedicated to paying social security benefits to the families of stone quarry workers who die with silicosis.
And workers have sought redress. In 2019, South African gold miners who contracted the disease won a landmark $US332-million class action settlement.
In February, the owner of Spanish kitchen benchtop manufacturer Cosentino accepted a six-month suspended prison sentence for five counts of serious injury due to gross negligence. He also agreed to pay 1.1 million euros ($1.7 million) in compensation to five stonemasons who had sued him for failing to warn of the risk of silicosis linked to cutting and polishing counter-tops manufactured by the company.
Is silica really the new asbestos?
Hoy doesn’t like the reference to silica being the new asbestos for two reasons. First, there is nothing new about silicosis. Secondly, while silicosis and asbestosis share some similarities, inhaling asbestos can also cause mesothelioma — a cancer affecting the mesothelial cells, which cover most internal organs. The dose of exposure causing mesothelioma is far lower than the dose of silica causing lung cancer. “This is why asbestos that is degrading in buildings around Australia is a far bigger problem than silica in place in building materials such as the benchtop in my kitchen,” he says.
Unless you decide to take an angle grinder to your sleek kitchen bench, the undisturbed silica inside will remain harmless, and doesn’t pose the same disposal problems as asbestos. Even so, Carey says she often encourages people to reconsider their use of artificial stone in the kitchen because of the harm it can cause to workers handling the product.
“There are alternatives – we can go back to laminate or natural stone, or wood. We don’t have to be using engineered stone.”
Caesarstone, a major manufacturer of artificial stone, says its products come with clear warning labels for use and that regulators – not manufacturers – are responsible for ensuring workplace health and safety measures are followed.
“Almost all substitute materials – except wood – and all stone encountered in construction and tunnelling contain some level of silica, which means they must be handled with exactly the same safety procedures and equipment as engineered stone.”
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