Tunnel construction workers across Australia say they face significant exposure to silica dust, research by the University of Sydney has found.
The research, published in the Australian and New Zealand Journal of Public Health, is based on a survey of 290 tunnelling industry workers and industry professionals between September 2024 and June 2025. It highlights a potential critical gap between awareness of silica risks and the effective implementation of safety controls.
“Workers understand the risks, but the survey results indicate that systems in place are not consistently protecting them. This is not a knowledge gap: it’s a failure of leadership, accountability, and enforcement, with workers ultimately paying the price with their heath,” said lead researcher and PhD candidate Kate Cole from the Faculty of Medicine and Health, who has worked on large-scale infrastructure and construction projects, including tunnelling, for more than two decades.
There is widespread recognition of the dangers, but 62.5% of survey respondents reported barriers preventing effective dust control, with time pressures, lack of management commitment, and weak regulatory enforcement identified as key issues. Most were concerned about being exposed to silica dust and developing a silica-related disease.
The key findings from the survey are:
- 14.2% of participants reported having a silica-related disease or condition, most commonly chronic bronchitis, silicosis or rheumatoid arthritis.
- Conditions for most work groups (groups of workers performing similar tasks) were judged by experts to exceed workplace exposure limits for silica dust.
- Nearly half of survey respondents did not believe regulators were effective in promoting safe practices, with workers reporting the lowest confidence in dust control measures.
- Advance notice of inspections is given, with several survey respondents claiming that workplace conditions are being temporarily modified so that projects appear compliant with dust control measures. One respondent said: “They can’t see what really happens when they’re not there, sites are informed of the visit and make it look good, numbers are botched, readings not true – it’s like they come in, tick their boxes and away they go”.
The survey found that workplace culture and project pressures tended to prioritise production over safety, according to surveyed workers who described environments where raising concerns could risk job security, and where dust control measures were sometimes deprioritised to meet tight deadlines.
“Some participants reported conditions so dusty they could not see more than a few metres ahead,” said Cole.
While most surveyed workers said air monitoring was conducted on their worksites, trust in the results was low. Many raised concerns that monitoring may sometimes be carried out under workplace conditions that were artificially altered to appear better than they typically would be, with these results not consistently shared.
“This points to a lack of transparency and accountability,” said Cole.
The survey acknowledges improvements in dust control technologies over the past decade, including better ventilation systems, enclosed cabins, and increased use of respiratory protective equipment. However, the researchers warn that it’s possible, based on the survey results, that measures may not be being applied consistently, or that they may too often be relied on instead of controlling hazards at the source. The study calls for stronger regulatory enforcement and oversight of the industry, noting that while unions and regulators were key influencers, their effectiveness was viewed inconsistently by respondents.
“With Australia’s infrastructure pipeline continuing to expand, without systemic change, preventable disease will remain an ongoing risk for thousands of workers,” said Cole.
In recent years the dangers of exposure to silica dust have been highlighted in Australia. In 2024, the Australian Workers Union warned of a silicosis tsunami coming for Sydney metro tunnellers.
Last year the New South Wales government established an expert taskforce to oversee and help address silica-related health risks for workers and a Silica Worker Register to monitor and track the health of at-risk workers.
