Experts may have found a link between living in the country and a higher risk of developing Parkinson's disease, according to MailOnline.
Researchers at the IRCCS University Hospital San Matteo Foundation in Pavia, Italy analyzed more than 100 studies from around the world, they concluded that weed and bug killers increased the risk of developing Parkinson's disease by 33 to 80 percent.
There is currently no cure for Parkinson's disease, a neurological disorder that is characterized by a deficiency of dopamine. Some symptoms of the condition are slow movement, stiff muscles and shaking.
Parkinson's mainly develops in people over 50. About five in 1,000 people in their 60's have the disease and about 40 in 1,000 people in their 80's struggle with it.
The team took into account factors that might increase a person's exposure to the correlated chemicals, such as living in the country, occupation, and if their drinking water came from wells.
"Due to this association, there was also a link between farming or country living and developing Parkinson's in some of the studies," said author of the study, Dr. Emanuele Cereda.
The study especially linked the weed killer paraquat and the fungicides maneb and mancozeb with twice the risk of developing the disease.
Dr. Cerada claimed the study did not look at which types of exposure were riskier, such as whether the substance was inhaled or sprayed on the skin.
"However, our study suggests that the risk increases in a dose response manner as the length of exposure to these chemicals increases," Dr. Cerada said.
The limitation on the study was that the authors were not able to assess the effects of secondary causes of the disease, the authors are calling for more research in order to bring these factors into account, reported Medpage Today.
"We're only starting to open that black box and understand the details of how that works chemically within the human body, but we're making progress very fast," said Dr. Arch Carson, MD, PhD, of the University of Texas School of Public Health in Houston. "This study is a benchmark in that process."
Dr. Carson recognizes the holes in the study, but believes it is still a good step towards understanding the cause of Parkinson's.
"This report is the first to show that there is a positive relationship between not only insecticides and herbicides but also some other solvent chemicals to which many people are exposed and the development of Parkinson's syndrome," Dr.Carson said.
