More stories have surfaced of illness and death among people exposed to a fumigation pesticide on the Wellington waterfront.
Scientific tests have not conclusively linked the pesticide to neurological diseases, but workers and their families are concerned about the effects of exposure to methyl bromide.
Last month The Wellingtonian reported that methyl bromide was being used at Wellington's port to fumigate export logs, with the used gas released to the atmosphere.
Rick Graham of Lower Hutt died of motor neurone disease in 2007.
He had spent some years inspecting used cars on the wharf after they had been fumigated with methyl bromide, also known as bromomethane.
Ngaio resident Ian McGregor worked on the waterfront from the early 1970s as a refrigeration engineer.
He has been crippled by motor neurone disease and is in fulltime hospital care.
"I can't write; I can't hold a pen, or a knife and fork," he said, speaking slowly and haltingly.
He said he believed his condition was caused by exposure to methyl bromide on the waterfront, where export logs were fumigated under tarpaulins.
No-one working on the wharf was aware of the risks, he said. "They told us bugger all - nothing."
Another man, who we agreed not to name, said that last year he suffered a grand mal epileptic seizure, which he attributed to lingering methyl bromide after exposure to imported used cars.
The man, in his mid-40s, works in the Wellington automotive industry and said he feared for his job if he was identified.
"When I go near a car that has been fumigated, I get massive headaches and feel nauseous," he said.
A friend who works in the same business for another company suffers even worse symptoms.
"He can't even hop into those cars to do his part of the job. Somebody else has to do it."
After cars were fumigated with methyl bromide they were marked, he said. "By law they have to put a sticker on them. If it's safe, why do they have to do that?"
Otago University pesticide toxicology specialist Leo Schep said methyl bromide was a gas that dissipated as soon as it was released.
"Once you lift the tarpaulins it just goes straight up," he said. "It will dissipate. Once it comes out of the wharf it's gone."
Agricultural use of methyl bromide has been phased out since its damaging effect on the ozone layer was identified.
Users in New Zealand must install a full recapture system for used gas by 2021.
Asked whether it was possible people could have been affected by cars that had been fumigated, Mr Schep said the gas was unlikely to be present after vehicles had been removed from the wharf.
"From the Act point of view, people in cars are not going to be exposed to methyl bromide, but from the cause-and-effect point of view, I would reserve judgement."
Low-level exposure to methyl bromide has been suspected of causing motor neurone disease.
High-level exposure has caused nausea, abdominal pain, headaches, confusion, convulsions, limb spasms, seizures and impaired vision. It can be fatal.
- The Wellingtonian