By SIMON COLLINS, KEVIN TAYLOR, MARTIN JOHNSTON AND ANNE BESTON
Thirty-nine years after a midwife saw "horrific" deformities in babies born near a New Plymouth chemical factory, an official study has found dioxin levels in the blood of local people as high as those in people sprayed with Agent Orange in the Vietnam War.
The study of 24 people who lived within 2km east or 1km south of the Ivon Watkins-Dow chemical plant between 1962 and 1975 found that their average level of dioxin was three times the national average.
It was similar to some dioxin levels - but not as high as the highest - reported recently in areas of central and south Vietnam that were sprayed with Agent Orange 20 to 28 years previously.
Ministry of Health officials said such high dioxin levels could cause up to three extra deaths from cancer in every 100 people.
It is not known how many people may have died, or could die, from cancer as a result of dioxin exposure.*
Another study, published in 1997, found that contractors who sprayed 2,4,5-T for an average of 16 years had 10 times the national average level of dioxin in their blood.
Calls for compensation were made yesterday.
The strongest came from New Plymouth MP and Government minister Harry Duynhoven, who said proper compensation should be paid when significant evidence was found showing that the company, now called Dow AgroSciences, was responsible.
But Associate Health Minister Damien O'Connor said talk of compensation was premature.
He said talks between Dow AgroSciences and the ministry had been held about the study, but compensation was not discussed.
When asked if the Government would sue Dow, the Health Ministry's acting director of public health, Dr Doug Lush, said: "The ministry has a duty to protect public health. It's one of the possibilities."
Community campaigner Andrew Gibbs, of the Dioxin Investigation Network, emerged fuming from a closed-doors meeting between some community representatives and health officials yesterday.
"I'm furious. We've been saying for four years that there were Vietnam-level exposures.
"They now prove it and turn around and say, 'We are not going to do anything else'.
"This thing dwarfs thalidomide." This is the biggest environmental cover-up this country has seen."
In a statement yesterday, Dow AgroSciences said the study findings concerned exposure 40 years ago to operations that had long since ceased.
No one tested had been found outside the range of what would be considered normal background levels of dioxin in other studies.
Dow's 2,4,5-T was the most heavily used spray for gorse and blackberry on New Zealand hill country farms in the 25 years to 1987.
The latest report, by the Institute of Environmental Science and Research (ESR), ends almost 40 years of official denials that the dioxin used in making 2,4,5-T at New Plymouth may have affected the health of local people.
It found that the level of dioxin in the blood of nearby residents increased directly in relationship to how close they lived to the Dow factory and how long they lived there before 1987.
"Only one person of 12 who lived in the area less than 20 years in the period 1962-87 showed a significant elevation in [dioxin], while eight of 12 living in the area for at least 20 years had highly significant elevations."
Men aged 65 and over who had lived in the area for an average of 29 years since 1962 had dioxin levels 4.9 times the national average for their age group.
Men aged 50 to 64 had dioxin levels 3.9 times the average for their age group, women aged 65 and over three times the average, and women aged 50 to 64 twice the average levels.
A study two years ago of dioxin levels in soil around the Dow plant found higher levels in an area extending about 1km east of the factory and about 400m southwards, in line with prevailing winds.
ESR concluded that the dioxin was spread by air in the years before 1975, when the company started incinerating its wastes.
High chimneys spread the incinerated waste more widely, but much more thinly, from 1975.
The ESR found no evidence that people in the area who grew their own vegetables or ran hens had higher levels of dioxin than others, supporting the indications that dioxin was spread through the air rather than in the soil.
The study also found that the only type of dioxin that showed up at above-average levels was 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a component of a chemical used to make 2,4,5-T.
Dr Lush said the study showed that the suburb of Paritutu, where Dow is based, is a safe place to live, "as safe as any other New Zealand suburb".
Dr Lush said a further 20 people's blood would be tested. Testing was not being extended to others in the suburb or elsewhere.
Mr O'Connor said the rest of the study should be finished by the end of the year. Another study, of New Plymouth cancer rates, should also be finished by then.
Responding to claims of a cover-up, Dr Lush said the exposure to dioxins occurred at least 17 years ago, and state agencies were giving as much information as possible to affected people.
They were not expected to face any extra medical expenses, and financial compensation for them "is not something we've considered today".
A Taranaki medical officer of health, Dr Patrick O'Connor, said studies had found an increased cancer death rate near the plant and an increased birth defect rate in New Plymouth, but neither finding was significant in statistical terms.
* Dioxin levels three times above the national average have been found in 24 people who lived near a New Plymouth chemical factory between 1962 and 1975.
* Up to 139 people who lived in the area in the period up to 1987 may have died, or will die, from cancer caused by exposure to dioxin.
* There is still no evidence whether dioxin also caused birth deformities first reported in the area 39 years ago.
What happens next
* Another 20 people who lived in the area between 1962 and 1987 will be tested in the next four months.
* The Health Ministry is studying New Plymouth's rates of types of cancer associated with dioxin exposure.
* Affected residents are considering suing Dow AgroSciences, and possibly the Government, for compensation.
* CORRECTION: In the original version of this report we stated incorrectly that as many as 139 people may have died, or would die, as a result of dioxin exposure in the 500 affected households. It is not possible to calculate this number with data currently available.
Herald Feature: Dioxin
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By SIMON COLLINS, KEVIN TAYLOR, MARTIN JOHNSTON AND ANNE BESTON