About 200 people attended the forum in Belconnen, the second meeting of residents worried about their health and their children’s health as a result of living in contaminated homes.

Dr Pengilley said the research would be difficult because the mesothelioma register dated to the 1980s. The dangerous loose-fill insulation was installed from the late 1960s through to the 1970s. He also said it would be difficult to track down the people who previously lived in Mr Fluffy houses.

He expected the risk of living in a home that contained the insulation would turn out to be quite low, but higher than the risk of developing asbestos-related risks in the wider community.

Asbestos was in the air everyone breathed all the time, given its use in so many building materials, he said. Until recently, every time a bus used its brakes a burst of asbestos fibres was released because brake pads had been made of asbestos. Biopsies of lungs suggested asbestos was present in the lungs of most Australians, he said.

While low exposures could cause disease, the risk increased with intensity of exposure or time, he said. Short, sharp exposures such as during home renovations increased risk, as did lower exposures over a long period. When he asked how many people at Sunday's forum had done home renovations, most put up their hands.

But even with high exposures, most people would not get sick, Dr Pengilley said, pointing out that the vast majority of people in the Western Australia asbestos mining town, Wittenoom, never developed an asbestos-related disease.

Among home renovators exposed to asbestos, five in 100,000 people a year developed mesothelioma after 35 years, he said. Among Wittenoom residents, the annual risk of developing mesothelioma was 26 in 100,000. Mesothelioma is a cancer of the lining of the lungs. Two Mr Fluffy residents have been diagnosed with the disease this year; one recently died.

Asbestosis is another asbestos-caused disease, but Dr Pengilley said he did not expect people living in Mr Fluffy homes to develop the condition, which was marked by scarring on the lungs and breathing problems. He said asbestosis was generally seen in people who had been exposed to a lot of asbestos.

The residents at the forum questioned officials about risks to their health, both physical and psychological, and the potential for the loss of their homes and "everything they've worked for".

Some urged fellow residents to stay calm given the low risk, while others warned against complacency.

The forum heard concerns about the quality of asbestos assessments and the difficulty of notifying tradespeople, family and friends who had been in contaminated homes.

The head of thoracic medicine at Canberra Hospital, Mark Hurwitz, said experts were divided on the value of having a chest X-ray. But in his view it was worthwhile as a baseline with which to compare health problems that occurred down the track.

Chest X-rays were of low-dose radiation – the same as flying to Brisbane – he said. But he stressed they had no value for predicting whether you would get sick later.