ABERDEEN, Scotland, May 31 (UPI) -- Pesticides and traumatic head injury may have a causative role in Parkinson's disease, according to a Scottish study.
The risk of developing Parkinson's disease increases according to the level of exposure, according to the study published online ahead of print in the journal Occupational and Environmental Medicine.
People who had been exposed to low levels of pesticides were found to be 1.13 times as likely to have Parkinson's disease compared with those who had never been exposed, while those who had been exposed to high levels of pesticides were 1.41 times as likely to be affected, the study said.
Parkinson's disease occurred 1.35 times more frequently in people who had been knocked unconscious once compared with those who had never been knocked out, and arose 2.53 times more frequently in those who had been knocked out more frequently.
British occupational safety limits were used as a standard. The study involved 959 prevalent cases of parkinsonism -- 767 with Parkinson's disease -- and 1,989 controls recruited in Scotland, Italy, Sweden, Romania and Malta.
