Workers responsible for major transport projects might have been exposed to unsafe levels of cancer-causing dust, which has already prompted a nationwide ban on engineered stone.
The Australian Workers Union said tunnellers who worked on Sydney's $21 billion metro line were routinely exposed to an unsafe level of toxic silica dust, pointing to air quality tests that showed repeat breaches of national safety standards.
Silica dust exposure can lead to workers developing silicosis, an incurable, debilitating and potentially fatal disease.
A number of concerned parties - including Lung Foundation Australia - are worried sandstone often found in the Sydney basin is exposing workers to the dust at an even-higher rate than engineered stone.
A nationwide ban on engineered stone, which contains a high level of silica dust, came into effect in July, but the dust remains a major concern for thousands of workers in other industries.
The Lung Foundation's submission to a NSW parliamentary review of the state's dust diseases scheme pointed out tunnellers were more likely to come into contact with silica dust than stonemasons had been before the ban.
"NSW has a large tunnelling industry which is an industry at high risk of silica dust exposure … of particular concern is tunnelling in Sydney as it is built on sandstone - a sedimentary rock which can contain up to 90 per cent silica dust," the foundation said.
"There are fewer regulations to protect workers against silica dust in these industries."
Sydney road projects including NorthConnex, WestConnex and the M6 extension all put workers at further risk, according to AWU assistant national secretary Chris Donovan.
"Sydneysiders would be ropeable if they knew the new metro they were sitting on, or underground motorway they were driving through, came at the expense of someone's health," he said on Tuesday.
"We need to find out what's happened underground in these projects right now so we can stop it happening in the future."
A Sydney Metro spokesperson pointed to a string of safety measures in place throughout the build including ventilation, respiratory protection and wet dust suppression.
"In almost all circumstances where results are above the exposure standard, the worker is protected by the respiratory protection they are using … (when) air quality tests do exceed the standard, numerous multi-level controls are implemented to prevent workers from being exposed," they said.
"Our construction partners have numerous strict controls in place to protect our workers from silica exposure during any activity where exposure presents a risk to health."
CPB Contractors, which built the metro line, said it had advanced risk-prevention techniques including tunnel ventilation and air filtration.
"(We) employ qualified occupational hygienists on every tunnelling project and have mandated the wearing of powered air purifying respirators, an advanced form of personal protective equipment," a spokeswoman said.
"We were the first to undertake advanced health screening, while also providing workers with access to leading medical expertise through their mandatory personal health management plans."
