Tests on radiofrequency emissions, biological agents and volatile organic compounds have failed to establish any link as yet to the seven cases of brain tumor among workers at the RMIT University.
Five of these seven cases were employees who had worked on the top floor of the Bourke Street block which has prompted the staff union to demand an explanation before the offices could reopen.
'We've been very clear: if you can't find a cause and it remains a mystery, then they (staff) don't go back because you've still got a problem,' Jeanette Pierce, National Tertiary Education Union branch president at RMIT, said.
The seven employees were administration and academics staff, who had been diagnosed with varying forms of brain tumors since 1999. Of this one is believed to be terminal.
RMIT University has not made any decision over the future of the building stating that they would consider the test results before making any decision. However a spokesman said. 'But our position has been that the relocation (of staff) was temporary pending the testing.'
According to the university a preliminary assessment of the patients revealed 'no obvious link between the tumors detected and any specific environmental hazard in Building 108'.
'The tumors detected have varying origins and only three of the seven lesions have known associations with radiation,' said John Gall, of Southern Medical Services.