Pesticide exposure could speed up the development of Parkinson's disease in people who are prone to the disorder, according to the results of a new study.
The study, involving lab mice, examined the effects of low-level exposure to dieldrin, a banned pesticide. The results point to brain changes that could advance Parkinson's disease.
"Our current study shows that pesticides such as dieldrin appear to accelerate or exacerbate the already underlying disease," the research team concluded in a statement released at a recent meeting of the American Chemical Society in San Francisco.
"Pesticides aren't necessarily the causative agents, but they do promote Parkinson's. So it appears the more you are exposed to pesticides, the greater your risk of development of the disease earlier in life."
Parkinson's disease is characterized by tremors, stiffness and slowness of movement. It results from the gradual death of brain cells that produce dopamine, a chemical that plays a key role in smooth muscle movements.
"We think pesticides in the brain tissue increase oxidative damage and alter dopamine handling," one of the researchers, Kurt Pennell of the Georgia Institute of Technology, said in an e-mail.
Although no longer in use, dieldrin can persist in the environment for decades and move up through the food chain -- particularly in dairy products and meats -- to humans, Dr. Pennell said.
This is not first time that chemicals have been implicated in the development of Parkinson's disease. A study released earlier this year also suggested that chronic exposure to pesticides and herbicides could damage dopamine-producing brain cells.