Demolition debris a health danger?
Working or living close to demolition sites increases risk of dust-related health problems, says a toxicology professor.
Professor Ian Shaw, of the University of Canterbury, said attempts to reduce demolition dust in the city were "variable" and often ineffective.
Residents and workers had been exposed to a lot more dust than in "pre-earthquake days", increasing health risks, he said.
"For most of us this is a very small increase but for demolition workers the risk is much greater."
Asbestos was of concern, but it was "a well-known dust carcinogen and is taken very seriously by building deconstructors".
Shaw said fine respirable concrete dust particles, however, could also lead to potential health risks.
"Studies on workers exposed to concrete dust have shown that crystalline silica is the problem and that it is associated with a broad array of lung diseases, including silicosis and lung cancer," he said.
Demolition of concrete buildings "inevitably produces crystalline silica dust".
The effect of the toxin on health depended on dose, Shaw said.
People who worked with concrete dust were in the top exposure bracket, while the general public were at the bottom.
"A bit higher up the exposure spectrum are people like me who sit in offices with demolition close by for weeks or even months," he said.
"It is very difficult to link exposure to effect, but data from the United Kingdom clearly show that there has been an increase in incidence of mesothelioma – "asbestos cancer" – with time and that the incidence is very much greater in men.
"This suggests occupational exposure; however, women's mesothelioma incidence has increased too ... [suggesting] general environmental exposure to asbestos is also a factor."
Christchurch woman Sara Andrews, whose sister died of mesothelioma in 2010, said she was concerned about Christchurch rebuild workers' and residents' exposure to asbestos as well as their rights for compensation should illnesses develop.
"In 20 to 30 years time it will not be surprising to see claims from residents and from those from Ireland, England and other countries. What are the rights of immigrants to Accident Compensation Authority (ACC) claims?
"The Government will need to build up their ACC coffers to deal with these claims," she said.
"It does not require long and intense exposure to asbestos to become a victim of this poison.
"ACC and its supporters try to downplay and negate this fact."
Canterbury District Health Board medical officer of health Alistair Humphrey said the register of asbestos-related illnesses for the last 30 years had about 400 cases, 99 per cent of which were due to prolonged, chronic exposure to asbestos in the workplace.
"There is this idea that a single exposure can kill you, but it doesn't though. It is similar to the idea that every cigarette causes you harm. Yes, it does, but will you get lung cancer from a single cigarette? Unlikely, but possible."
University of Canterbury law lecturer Professor Stephen Todd said if a person contracted an asbestos-related illness in the course of doing their job it would be covered by ACC.
But if a resident rather than a worker suffered harm, they would have to try suing.
"I do not know of any case in New Zealand where a common law claim has been brought. Should this issue arise it would be a difficult question, which the courts would have to resolve in the light of the United Kingdom cases.
"Mesothelioma has a very long latency period – typically 30 or 40 years – and the difficulty in proving liability after that period may be acute," he said.
ACC spokeswoman Stephanie Melville said there had been regulations controlling the use and exposure to asbestos since 1978.
"It has been expected that the number of cases of asbestos-related diseases presenting will have peaked or reached a plateau and there may be a reduction in the number of cases going forward," she said.
Melville said if a builder was exposed to asbestos during demolition or rebuild work following the Christchurch earthquakes the health effects would not be seen for many years.
"ACC has been assured by the Department of Labour and the Public Health Unit of the Ministry of Health that there is an awareness of this hazard and that air quality is being monitored ... " she said.
A spokeswoman for the Canterbury Earthquake Recovery Authority said its contractors were required to follow rules set by the Ministry of Business, Innovation and Employment when dealing with asbestos.
That same year, Sara Andrews' sister was formally diagnosed with mesothelioma.
It was days before her 39th birthday.
Michelle Mary Andrews died on May 21, 2010, aged 41.
Her battle with mesothelioma, which affected the outer lining of her lungs and chest cavity, started two-and-a-half years earlier.
Michelle was 38 when she was admitted to Lower Hutt Hospital in 2007.
She had just done 50 lengths at her local pool - at a very slow pace.
Something was not right. Her breathing was laboured, her fingers were blue and her pulse was racing.
At Lower Hutt Hospital, doctors discovered two litres of fluid in her chest.
Michelle was there for six weeks and formally diagnosed with mesothelioma on January 11, 2008.
Sara, 46, says it was "awful" watching her sister struggle to breathe and walk.
It was horrible watching her panic when she could not get air into her lungs properly.
"It is very aggressive and people do not have much time to live once they are diagnosed."
Michelle was "quite the warrior", however, and "connected with others around the country who had mesothelioma or loved ones with cancer".
"She was extremely brave and determined. The emotional times were very difficult. She was rather angry at what she would not live to experience. She felt it very unfair," she says.
Sara says her sister was exposed to asbestos while working in storage buildings at the supermarket their parents owned in Wellington.
"We all worked there from a young age in paid employment . . . They later knocked down the buildings and built a new supermarket, which we all worked in."
Her sister encountered "major issues" in dealing with ACC. It denied her initial claim, in 2008, so she sought help from Wellington accident compensation experts John Miller Law. A second opinion won her the ACC case about 18 months later.
"If she had won it on her initial work, she would have been able to utilise her final window to travel and enjoy her final times of quality of life," says Sara.
"People need to be careful of what they say to their GPs and to specialists in the medical system. If ACC deem it to be merely environmental exposure, they will not pay out for care and treatment."
In 2006, a Court of Appeal ruling resulted in an increase in payments for asbestos-related ACC claims.
A total $23,361,525 in lump sums was paid for 297 claims in the year to June 2007.
ACC spokeswoman Stephanie Melville said the ruling "clarified the interpretation of legislation regarding qualifying criteria for lump sum payments for work-related gradual process disease or infection".
Records show a total $59 million in lump sum payments has been paid for asbestos-relation conditions by ACC since mid-2003.
Melville says a fall-off in payments since 2006 reflects a "reduction in workplace exposure to asbestos in the 1980s".
ACC lump-sum payments for asbestos-related conditions for year ending June 30:
2007 $23,361,525 (297 claims)
2008 $7,254,373 (96 claims)
2009 $7,177,314 (89 claims)
2010 $6,875,782 (87 claims)
2011 $6,626,854 (71 claims)
2012 $5,741,258 (62 claims)