A new study has found that being exposed to pesticides, as well as suffering traumatic head injury raises the risk of developing Parkinson's.
The study, which is published online ahead of print in the journal Occupational and Environmental Medicine, one of the BMJ Specialty Journals, states that the two increase the risk of developing the disease.
959 people suffering with Parkinson's, as well as 1,989 controls recruited in Scotland, Italy, Sweden, Romania and Malta were used in this study.
As a part of the research the subjects completed a questionnaire regarding their lifetime occupational and recreational exposure to solvents, pesticides, iron, copper and manganese.
Their lifetime exposure was then estimated blind to disease status and the results were adjusted, as appropriate, for age, sex, country of residence, tobacco use, ever having been knocked unconscious and family history of Parkinson's disease.
The researchers noted that while low exposure to pesticides increases the risk of developing the disease by 1.13 times, exposure to high levels of pesticides increases the risk by 1.41 times.
The researchers noted that while people who had been knocked unconscious once were 1.35 times more likely to develop Parkinson's, while it was 2.53 times more likely in those who suffered a head injury more often.
However, the researchers who conducted the study also insisted that these two risk factors are ones that can be controlled to a certain extent.
Traumatic head injury can be prevented by not indulging in contact sports such as boxing.
As for pesticides, well the researchers argue that further research could identify more specifically which pesticides are associated with this effect, so that these agents can be substituted.
The study, which was funded by The European Commission, is one of the largest case-control studies to date of genetic, environmental and occupational risk factors for Parkinson's disease or other degenerative parkinsonian syndromes.