Exposure to pesticides and solvents is associated with a higher risk of developing Parkinson's disease, an analysis of more than 100 studies from around the world has found.
The research published in Neurology, the journal of the American Academy of Neurology found that exposure to bug or weed killers and solvents increased the risk of developing Parkinson's disease by 33 to 80 per cent.
"Due to this association, there was also a link between farming or country living and developing Parkinson's in some of the studies," said study author Emanuele Cereda, with the IRCCS University Hospital San Matteo Foundation in Pavia, Italy.
Parkinson's disease is one of the most common neurological disorders affecting 22 out of every 10,000 individuals. It is a degenerative, progressive disorder of the nervous system that affects the movement of the limbs and facial muscles.
For the analysis, researchers reviewed 104 studies that looked at exposure to weed, fungus, rodent or bug killers, and solvents and the risk of developing Parkinson's disease.
Studies that evaluated the proximity of exposure, such as country living, work occupation and well water drinking were also included.
In controlled studies, exposure to the weed killer paraquat or the fungicides maneb and mancozeb was associated with two times the risk of developing the disease.
"We didn't study whether the type of exposure, such as whether the compound was inhaled or absorbed through the skin and the method of application, such as spraying or mixing, affected Parkinson's risk," said Cereda.
"However, our study suggests that the risk increases in a dose response manner as the length of exposure to these chemicals increases," Cereda said.
