More than a year after being asked to investigate alternative for the toxic fumigant methyl bromide, Wellington's Centreport appears to have done nothing.
Methyl bromide, also known as bromo-methane, is lethal to all life forms and has been widely used on the waterfront for fumigation of exported and imported products, particularly logs.
In June 2011, the New Zealand Environmental Protection Authority gave local users 10 years to institute systems to recover all used gas.
However, there appears to have been no move on Wellington's wharves to do so and the lethal gas is still being released into the atmosphere.
Some countries stipulate that certain exports must be fumigated with methyl bromide to kill insects and eliminate disease.
In the past this has been done under tarpaulins in the open, but with rising awareness of its toxicity, the practice has moved into shipping containers or ships' holds.
The main cause for concern around the gas is a suspected link between it and motor neurone disease.
Six cases of motor neurone disease around Nelson port between 2002 and 2005 have cast doubt on methyl bromide's safety, even diluted in the air.
The rate of motor neurone disease in the general population is only 1.8 per 100,000 people. However, there were 16 cases in the entire Nelson-Marlborough area (population 140,000) in that period.
A 2005 report into the outbreak in New Zealand Medical Journal by toxicologist Ian Shaw concluded that methyl bromide exposure could have been a factor.
A second report, by Nelson-Marlborough medical officer of health E Kiddle, concluded that the six cases near the port were probably due to chance, but recommended that methyl bromide be treated with caution and investigated further.
So far there has been no clear evidence of motor neurone disease around Wellington's port.
Maritime Union general secretary Joe Fleetwood said he was unaware of any cases of motor neurone disease among Wellington port workers, but the union had actively campaigned against the use of methyl bromide.
A regional public health spokeswoman said the disease was not notifiable, so there was no record of it at or around the Wellington port.
David McLean, who is researching motor neurone disease at Massey University, said from statistics between 1998 and 2003, dockworkers appeared twice as likely as others to die of motor neurone disease.
However, because that was only four deaths in 741, it was too few to be statistically significant, he said.
Although methyl bromide breaks down in the atmosphere, it depletes ozone levels and the United Nations Environment Programme Ozone secretariat has required signatories to the Montreal Protocol, including New Zealand, to phase out its use.
CentrePort chief executive Blair O'Keeffe said logs and other cargo were fumigated on the waterfront "in full compliance with health, safety and environment rules".
The work was carried out by third parties licensed by the New Zealand Environmental Risk Management Agency.
The company was committed to ensuring a safe environment for its employees, tenants and neighbours, including the safe fumigation of logs using methyl bromide gas to control insects and rodents, he said.
Mr O'Keeffe said he appreciated people were concerned about methyl bromide, and the company was involved in programmes to find alternative fumigation.
Other ports, such as Nelson, had moved fumigation into warehouses to recapture the gas, but the technology was not scalable or suitable for bulk export cargoes such as logs, he said.
QUESTIONS CENTREPORT DIDN'T ANSWER
- Had CentrePort noted Professor Shaw's report and accepted its conclusion?
- Had it made any changes as a result, and what were they?
- Had CentrePort attempted to find out whether there had been any cases of motor neurone disease among its workers?
- Had any assessment been carried out on the health risk to personnel from the continuing use of methyl bromide?
- Had any assessment been carried out of the financial risk to the company and the two councils that own it if methyl bromide ever proves to be a cause or significant factor in motor neurone disease?
MOTOR NEURONE DISEASE
Motor neurone disease is a neurological condition which causes degeneration of certain brain and spinal-cord nerve cells.
Its causes are not known and it is fatal within four years of diagnosis.
Initial symptoms can include muscle spasms, exaggerated reflexes and a progressive wasting of muscles controlling speech, chewing and swallowing.
Patients can lose the ability to walk, speak, use their arms and hands, or hold up their heads.
Motor neurone disease is most commonly diagnosed between the ages of 50 and 70.
There is no cure or effective treatment, although symptoms may be managed with drugs.
- The Wellingtonian