Motor neurone disease in the study spotlight

New Zealand’s first-ever comprehensive survey into links between motor-neurone disease and the workplace is to be undertaken by Massey University’s Centre for Public Health Research.

With new Health Research Council funding of $2.8 million, researchers led by Professor Jeroen Douwes, will investigate whether occupational exposures such as agricultural chemicals, electromagnetic fields, solvents, etc. may increase the risk of someone developing the disease. The study has the support of the Motor Neurone Disease Association of New Zealand.

Motor Neurone Disease is a progressive neurodegenerative disease that attacks the upper and lower motor neurones – nerve cells that control muscle movement. Degeneration of the motor neurones leads to weakness and wasting of muscles, causing increasing loss of mobility in the limbs, and difficulties with speech, swallowing and breathing. There is no cure or standard treatment for MND, and although palliative care has improved there is no treatment that will significantly alter its course. The Motor Neurone Disease Association of New Zealand notes that there are about 100 new cases each year and 300 cases in New Zealand at any one time.

The study, which the researchers hope will link in with new international studies, will recruit people with motor neurone disease and a comparable group without the symptoms to determine its possible causal effects, Professor Douwes says.

“It will allow us to not just look at cases and data in New Zealand but overseas and overall give us greater statistical power.”

The additional $2.8 million of research funding will also used for a concurrent study investigating occupational exposure to the fumigant methyl bromide.

Although highly toxic to humans and recognised as depleting the ozone layer, methyl bromide is used to fumigate soil and imported goods being held in quarantine, as well as export products such as logs and fruit.

Under international protocols, New Zealand is exempt from measures phasing out the use of the substance in relation to its use for quarantine and pre-shipment procedures.

Professor Douwes says this puts workers, who undertake the fumigation and those that open fumigated sea containers, potentially at risk of neurological and breathing disorders.

The Centre’s study will seek to determine the number of workers exposed to methyl bromide and assess their risk of neurological outcomes, survey those with neurological symptoms and compare them to others without such symptoms, and track participants with the use of computer assisted neurobehavioural testing.

In addition to the new funding by the Health Research Council, the centre is continuing with $2.8 million of research programme grants awarded in previous funding rounds. This includes studies of occupational asthma in sawmill workers and cleaners, a study of neurotoxic effects in solvent exposed workers, a study of causal exposures of occupational cancer in meat workers and an intervention study in joinery workers and furniture makers.

The new programme of research into occupational health represents a new direction for the centre based at Massey’s Wellington campus and indeed for New Zealand, into neurological research.

“It’s always good to get big grants but I really see this as a triumph for occupational health,” Professor Douwes says.

“Others compare us to UK but we’re more comparable to Denmark, Norway, Sweden and the Netherlands though they have better research capacity than here.”

In New Zealand we invest a lot less into occupational health research. Traditionally we have had very little interest in occupational disease despite the fact we have between 17,000-20,000 new cases of work-related disease per year, most of which are potentially preventable. If we are to reduce this we need to invest in research, and research that will result in effective interventions.”