A survey of residents of Fluffy-contaminated houses showed more than 80 per cent had renovated their homes, exposing not only themselves but buildings and other tradespeople to the dangerous loose asbestos fibres.
Well under half of the residents wore a mask or other protective gear when they did their own renovations, and of those who knew whether their builder had worn protective gear only half said they had.
The news comes from a survey of former and current Fluffy residents in 2016, made by the Australian National University team studying the health impacts of Canberra's Fluffy asbestos crisis.
"Given the high number of renovations … it is likely that a large number of builders and tradespeople have been exposed to loose-fill asbestos over time, knowingly or unknowingly," the report authors comment.
The survey only captured a minority of residents of the asbestos-contaminated homes, with 567 residents responding in all. Of them, 363 were recent residents and 204 people who had lived in a Fluffy home at some time in the past. There were fewer renovations among past residents.
Of the recent or current residents, one had been diagnosed with lung cancer and two with pleural plaques. One reported a spouse had died of mesothelioma.
Of the past residents, 10 had reported health problems they believed were caused by asbestos exposure. Five had been diagnosed, one with one with mesothelioma, another with lung cancer and one with nodules in the lungs, and two with pleural plaques.
The report authors said it was likely that many residents had been exposed to the fibres, given just over half had entered the roof space at least once, and almost two-thirds had entered the sub-floor.
Chief investigator associate professor Martyn Kirk said while people who had worked on the homes had potentially been exposed, it was impossible to quantify the implications for their health.
He stressed that while asbestos exposure increased the risk of developing mesothelioma and other cancers and tradespeople were at higher risk, the diseases were still "incredibly rare, even amongst people who have had high levels of exposure and have worked in it", and disease was related to level and time of exposure.
"… We wouldn't necessarily expect there to be much illness among people who have lived in these houses, disease caused by asbestos are very rare and take many years to develop," he said.
But the study highlighted significant stress among Fluffy residents.
Most reported said their health was good to excellent, but more than a third were very concerned or extremely concerned about the health impact of living in a Fluffy house.
"It can take 20-50 years for symptoms of mesothelioma to develop, so for half the residents in our study, they would not yet reached the approximate minimum 20 year lag period for symptoms to appear," the authors write. "The uncertainty around exposure to asbestos and the long time between exposure and symptoms of disease may explain the large number of respondents reporting high levels of concern."
The loose-fill asbestos insulation was blown into ceilings of homes between 1968 and 1979. It has been discovered in just over 1000 Canberra homes, which are now being demolished.
One in 10 of the people surveyed were in the house when the asbestos insulation was installed during the 1970s, and almost one in three lived through the federal clean-up of the late 1980s, when the bulk of the insulation was removed from ceilings.
Just over half of the homes tested positive in 2014 and 2015 for asbestos fibres in the living areas, matching data from the Asbestos Taskforce, although without air samples, the authors report, it is difficult to assess the risk. Fibres had been found most commonly in cupboards, followed by bedrooms and heating or cooling ducts systems.
The study also suggests that many Fluffy residents are still living with their furniture and other belongings in their new homes. About one-quarter said they had taken all their belongings. Nine per cent reported leaving all their belongings behind in the houses.