A new report has found the risk of asbestos-related illnesses to Canterbury residents is generally low, but homeowners say it offers little reassurance.
The review by the Royal Society of New Zealand and the Prime Minister's chief science advisor, Sir Peter Gluckman, has found that exposure to the potentially fatal building material was unlikely to have significant health effects on people living in houses that had undergone earthquake repairs.
Sir Peter hoped the review would reassure homeowners that the risk of developing asbestos-related diseases following brief exposure was very low.
The report also noted that exposure levels immediately after the quakes, when clean-up procedures were substandard, were unknown.
Read the full report (PDF, 1.5MB)
Listen to a summary
Aranui homeowner Linda Boyce is considering legal action after her home tested positive for asbestos four months after earthquake repairs were carried out in 2012.
She was worried that she and her husband were exposed to low levels of asbestos from their stippled ceilings, as there was dust everywhere when they moved back into their home after repairs.
"It's not just us, and if it does affect it, it'll probably hit us just before we retire ... We could be robbed of our retirement.
"But what makes me really angry is these people who have moved back in [after quake repairs] with young kids."
Mount Pleasant homeowner Tom Davies said he and his wife lived in their badly damaged home for almost three years without knowing about the presence of asbestos.
He said it only took one fibre to enter the lungs for a person to be at risk later in life.
"The medical advice is that it's not going to show up for 20 years," he said.
"I just have to accept that me and my family have been exposed to it ... I just have to hope and pray that nothing happens."
Mr Davies strongly supported the report's recommendation to ban the importation and continued use of asbestos products.
He said New Zealand asbestos regulations were "way below" those in the UK and Australia.
Christchurch real estate business owner Tony McPherson said he was concerned about the legacy of some asbestos-containing properties in the region.
He said people's homes were their biggest asset and buyers needed to know what they were dealing with.
He said a pre-sale disclosure document was "probably pretty warranted" and said the situation in Christchurch had highlighted the need for such disclosure.
Worksafe New Zealand would not comment on the matter and Fletcher EQR, which manages the Christchurch home repair programme, also declined.
'Risk game'
Canterbury Medical Officer of Health Alistair Humphrey said he believed some owners of quake-damaged homes could face asbestos-related health problems in future.
Dr Humphrey told Morning Report the report showed risks were higher for those working with asbestos than homeowners or occupiers but there was no way to know how much exposure was needed before it posed a health risk.
He said it was a "risk game" and about 9000 homes had not been properly cleaned up or assessed.
"Is it possible that any people in those homes would have had enough exposure? My view is it is possible that some of them would have had enough exposure to cause asbestos-related problems in the future."
Dr Humphrey backed the call in the report for a ban on the importation of asbestos-containing materials as a "no brainer".
Listen to Alistair Humphrey
Registered Master Builders chief executive David Kelly said the problem would be detecting asbestos in overseas products, as different manufacturing standards applied.
"We don't necessarily have good border protection around products, whether they're health and safety of this sort or others, so that's going to be the challenge for New Zealand."
Mr Kelly said it was relatively easy to source alternative materials and a ban should be seriously considered.
Listen to David Kelly
Associate Health Minister Peter Dunne said he was yet to read the report but there was general support across government agencies for a ban.