Reveals Link Between Pesticides and Motor Neuron Disease
(Beyond Pesticides, February 3, 2006) Regular exposure to pesticides may play a role in causing some cases of deadly motor neuron disease, new Australian research suggests. University of Sydney scientists have found some patients with the progressive paralyzing disease have differences in a gene known as paraoxonase, which is involved in breaking down organophosphate pesticides.
According to neurologist Roger Pamphlett, PhD, preliminary results from a survey of 900 Australians, including 300 people with motor neuron disease, suggested regular exposure to pesticides may increase a person's risk of developing the condition. The findings are in line with previously done northern hemisphere studies. (See Daily News 8/19/04).
The Australian researchers want to confirm the results in a much larger sample of people, including 1,000 motor neuron patients, before they publish their data in a scientific journal. A National Health and Medical Research Council grant will allow them to collect information from many more cases during the next five years.
The scientists have set up the first DNA bank in the southern hemisphere to investigate the environmental and genetic influences underlying motor neuron disease, which usually strikes people aged in their 50s and 60s. Little is understood about the causes of motor neuron disease which begins with either muscle weakness, muscle twitching or difficulty in speaking and progressively leads to paralysis. Most patients die within two to five years of diagnosis.
Associate Professor Dr. Pamphlett said the DNA bank was the first to cover an entire continent and was expected to provide new insights into motor neuron disease.
He said the only treatment at the moment was a drug called riluzole which increased a person's lifespan by a few months."It does work but the effects are modest. The treatment can slow the disease down but can't stop it or reverse it," Dr. Pamphlett said in an interview.
"Our study seems to be the first hint that paraoxynase could be involved but it isn't the whole story because it doesn't explain all the cases," he said before addressing the Australian Neuroscience Society's annual meeting in Sydney. The researchers hope that the results of their study can lead them to more effective treatments for the disease.
Organophosphates are a widely used class of pesticides, including chlorpyrifos, diazinon, malathion, and methyl parathion. Organophosphates are applied in houses for termite control, in communities for mosquito spraying, and in agriculture and on golf courses.