A premier hospital in Sydney, Australia has been cleared of suspicions that it could be generating cancer among its staff.
An investigation revealed that the Concord Hospital environs or its functioning had nothing to do with the 24 cases of breast cancer among its staff in the last nine years.
A hospital-wide investigation was instigated in May after five women who worked closely together were diagnosed with the disease.
Undertaken by the South West Area Health Service's public health unit, the investigation included an epidemiological study and an environmental assessment.
It found the 24 cases of breast cancer were not a cluster but given the age, size and composition of the female workforce, were consistent with the rate of breast cancer in the general community.
Concord Hospital general manager Danny O'Connor said the probe had found no evidence of an excessive number of breast cancer cases in any particular area of the hospital.
The women diagnosed with breast cancer all worked in the same three areas - psychology, nutrition and diatetics and food services.
"It is important that we are now able to reassure staff and the community that there was no breast cancer cluster at the hospital and that the working environment is safe and healthy," Mr O'Connor said.
"Staff were relieved and reassured. They were confident in the findings.
"They had been kept informed of the progress of the investigation over the last five months and so, in many respects, they were not surprised at the findings."
Mr O'Connor said the investigation included some staff members wearing measuring devices for a number of environmental hazards, including ionising radiation, radiofrequency radiation, asbestos, contaminated water, tobacco smoke and dioxins.
The investigation met international guidelines and was consistent with other studies of cancer clusters, he said.
"All of those measurements were satisfactory, met the relevant standards and in a number of cases, were below what was expected," he said.
Mr O'Connor also criticised media reports earlier this month that claimed the investigation was finished but the hospital was holding back the results to maximise publicity.
He said the report was not available until December 17.
"I thought it was grossly insensitive that people would be talking about the final report for something as important as a cancer cluster investigation when in fact the final report had not been produced," he said.
Sydney Cancer Centre director of research Bruce Armstrong, who investigated the cluster at the ABC's Toowong studio in Brisbane, said breast cancer was the most common cancer among women and rates had been steadily increasing.
"Breast cancer is sadly a common disease affecting one in 11 women over their lifetime," Professor Armstrong said.
"Most of the time, as in this case, potential cancer clusters, or groups of cancer, in one place, are found to be a normal occurrence or occur by chance."