Fumigant not risky: forestry industry

Concerns that the fumigation of logs and lumber might be linked to motor neurone disease have no scientific basis, says the forestry industry.

"Methyl bromide gas is obviously toxic at the doses used to fumigate logs. But outside fumigation envelopes or containers, it poses no risk to the public or to wharf workers who follow safety procedures," Stakeholders in Methyl Bromide Reduction (STIMBR) spokesman Gordon Hosking said.

Dr Hosking was reacting to reports of research at Canterbury University that showed a reaction when methyl bromide was mixed with glutathione, a protective chemical in living cells.

The scientists' hypothesis was that if the human cells were exposed, it would reduce the cells' ability to protect against repeated exposure.

Toxicologist Professor Ian Shaw said exposure of nerve cells to the chemical could trigger motor neurone disease.

However, Dr Hosking said Professor Shaw's findings did not prove that motor neurone disease and methyl bromide were linked.

"But the possibility that they might has alarmed maritime and wharf workers," he said.

"No one knows what causes motor neurone disease. So it is understandable that family members and fellow workers should see possible exposure to the gas as an explanation for cases involving workers at sites where fumigation is carried out.

"Their concerns were fully investigated in an official inquiry five years ago and no link was found. Further reassurance comes from more recent investigations by the Institute of Environmental Science and Research, Environmental Risk Management Authority and the Ministry of Health that also found no link," Dr Hosking said.

Methyl bromide is used at some ports to fumigate logs and lumber for export and some imported food.

"Internationally it is the most widely accepted biosecurity fumigant, because it is effective against a wide range of pests and diseases, safe when used correctly, and does not harm the treated produce," Dr Hosking said. "However, because it damages the ozone layer, the hunt is on to find alternatives."

- NZPA