A toxicologist hopes to apply for funding to step up research on a potential link between a timber fumigant and motor neurone disease.
A medical inquiry five years ago concluded it was pure chance that six men exposed to methyl bromide gas at Port Nelson all died of the same disease.
But Professor Ian Shaw says preliminary research at Canterbury University is indicating possible long-term neurological effects caused by the gas.
He says the next step is human cell research into whether there is specific damage to DNA after exposure to methyl bromide.
Professor Shaw says it is too early in his research for a submission to be made a review by the Environmental Risk Management Authority on the use of methyl bromide.