Frequently Asked Questions (FAQs)
Please click the following links to learn more about methyl bromide and its use in New Zealand as a phytosanitary fumigant gas.
1. Methyl bromide
2. Methyl bromide – International treaties, law and regulations
3. Methyl bromide – Use as a fumigant
4. Methyl bromide – Use in New Zealand
5. Methyl bromide – Seeking alternatives
Nelson cluster, Ministry of Health reports
In May 2005 Nelson’s Medical Officer of Health published findings of an investigation into a possible link between cases of motor neurone disease (MND) that had occurred in people who had worked in the Port Nelson area and methyl bromide. Methyl bromide is used as a biosecurity treatment.
The cluster investigation process involved finding cases of MND that have occurred in the region and then determining the presence of any cluster or increase in cases over that number expected to occur. Information on the cases was then obtained which might indicate any link to exposure to methyl bromide.
Sixteen cases of MND were identified as having lived in the Nelson-Tasman area and been diagnosed with MND since 1995. The Medical Officer of Health determined that this is consistent with the expected incidence of the disease. Six cases gave a history of having worked in the Port Nelson area. Three of these cases could have had episodes of exposure to methyl bromide through proximity to timber fumigation sites. No definite exposure could be confirmed. The Medical Officer of Health also reported that no evidence was found in the medical literature of methyl bromide being linked with MND. No cluster could be identified based on rates of MND for the Nelson population.
The most likely explanation for the group of cases who had a work history involving work sites in the Port Nelson area is chance. A number of recommendations have been made relating to the fumigation process and to assessing any risk to the health of workers in the area or the public in general.