Tunnel workers cutting the gigantic passages for Sydney's Metros have been exposed to toxic silica dust levels far exceeding those working in the

1 in 3 air quality tests during construction of Metro City & Southwest exceeded the Workplace Exposure Standard (WES), some by 208 times, according to documents obtained from Transport for NSW (TfNSW).

Air quality reports at the three Metro West sites currently being bored show that toxic silica dust levels have exceeded the WES 1 in 7 times. The WES is .05 milligrams per cubic metre.

Worryingly, the data shows tunnelling using roadheaders exposes workers to silica dust levels far greater than engineered stone kitchen benchtops, which were banned after an AWU campaign.