Māori are at greater risk of harmful occupation exposures than non-Māori, despite doing the same jobs.
A Massey University study surveyed more than 5000 people from around New Zealand to determine what risk factors they were exposed to at work.
The research suggested the contribution of the occupational environment to health inequities between Māori and non-Māori had been underestimated.
Dr Hayley Denison, who led the study, said for dust and chemical exposures the main differences related to Māori working in occupations where these exposures were more common.
However, for physical and organisational factors, the differences in reported exposure were not explained by job role.
"Even within the same job, Māori were more likely to be exposed to physical factors such as heavy lifting and loud noise, and organisational factors such as carrying out repetitive tasks and working to tighter deadlines when compared with non-Māori.
"Our research suggests there may be unconscious bias operating in workplaces in New Zealand, whereby Māori are given more risky tasks at work," Denison said.
The study showed that both Māori men and women were twice as likely to perform heavy lifting.
Māori women were twice as likely and Māori men three times more likely to be exposed to loud noise and Māori men were also almost three times more likely to regularly use tools that vibrate.
The study surveyed 2344 Māori and 2710 non-Māori participants. They were sampled from the New Zealand electoral rolls and invited to take part in a phone interview which included questions about current workplace exposures.