Nowadays the National Occupational Health and Safety Advisory Committee (NOHSAC) estimated there were 17,000-20,000 new cases of work-related disease in New Zealand every year.
Between 2500 and 5500 were new severe cases and around 75 per cent of these diseases occurred in men.
Wagstaff said cancer, respiratory disease, work/noise related hearing loss, and ischaemic heart disease were some of the most common work-related chronic illnesses.
"Many of these diseases are as long-lasting in consequence as physical injuries that occur. Many are terminal."
He said greater awareness of risks in the workplace that cause work-related illnesses was needed, along with the inclusion of workers in this process.
"Involvement of workers and their unions in assessing how to manage these risks [is needed].
"Workers are typically excluded from this assessment despite often having a wealth of knowledge of how to best manage the risks they are exposed to."
Training workers and health safety representatives and promoting their ability to stop work if they felt unsafe was also an important step to make, he said.
Wagstaff said the CTU supported the work being done by WorkSafe in leading targeted work-related illness/disease prevention programmes, but more research could be done.
"Better research [and funding for this research] into the causes of work-related ill health, including emerging illnesses and diseases arising from new chemicals or substances."
He said NOHSAC was set up in 2003 by the Labour Government and produced a number of reports into work-related illness but it was disbanded by the National Government in 2009.
"Despite the reports being a decade old, they are still regarded as relevant and up to date in terms of their conclusions."