People planning to use chemical pesticides in their garden may want to consider this. It's not going to hurt the popularity of organically grown fruits and vegetables, either.
http://www.sciam.com/article.cfm?chanID=sa003&articleID=000BE289-5BAD-149D-9BAD83414B7F0000Study Bolsters Link between Pesticides and Parkinson's
June 26, 2006
by Karen Schrock
People who have been exposed to pesticides are 70 percent more likely to develop Parkinson's disease than those who haven't, according to a new study. The results suggest that any pesticide exposure, whether occupationally related or not, will increase a person's risk of the disease. This means that using pesticides in the home or garden may have similarly harmful effects as working with the chemicals on a farm or as a pest controller.The research,
published in the July issue of Annals of Neurology, provides the strongest evidence to date of the link between pesticide exposure and Parkinson's. The study included over 143,000 men and women who completed extensive lifestyle questionnaires beginning in 1982, and follow-up surveys through 2001. All subjects were symptom-free at the beginning of the project, when they were asked about their occupation and exposure to potentially hazardous materials. Since then, 413 of them have developed confirmed cases of Parkinson's, with a greater incidence of the disease in those who spent time around pesticides. "Low- dose pesticide exposure was associated with a significant increase in risk for Parkinson's disease," says lead author Alberto Ascherio of the Harvard School for Public Health. "I think this is one reason to be careful about using pesticides in general."
Although the causes of Parkinson's are not well understood, it has long been suspected that environmental factors play a large role. Animal studies have shown that chemical compounds commonly used as pesticides can cause a degeneration of dopamine-producing neurons. In Parkinson's, a shortage of dopamine causes the disease's characteristic motor abnormalities, including muscle tremors and muscle rigidity. Previous small-scale human studies had suggested a link between pesticides and Parkinson's, but this new study is the first to establish a clear correlation in a large patient population.
The researchers also looked for links between Parkinson's and other environmental contaminants, including asbestos, coal dust, exhaust, formaldehyde and radioactive material. They found no correlation between the disease and any of the materials besides pesticides, however. Because of the design of the questionnaires, the study was not able to determine how the frequency, duration, or intensity of pesticide exposure affected the incidence of Parkinson's. The next step, according to Ascherio, is to figure out which class of chemicals is actually causing the disease, so that people can reduce their exposure.
http://www3.interscience.wiley.com/cgi-bin/abstract/112660877/ABSTRACTAnnals of Neurology
Early View (Articles online in advance of print)
Published Online: 26 Jun 2006
Copyright © 2006 American Neurological Association
Pesticide exposure and risk for Parkinson's disease
Alberto Ascherio, MD, DrPH 1 2 *, Honglei Chen, MD, PhD 3, Marc G. Weisskopf, PhD 1, Eilis O'Reilly, MSc 1, Marjorie L. McCullough, ScD 4, Eugenia E. Calle, PhD 4, Michael A. Schwarzschild, MD, PhD 5, Michael J. Thun, MD 4
1Department of Nutrition, Harvard School of Public Health, Boston, MA
2Department of Epidemiology, Harvard School of Public Health, Boston, MA
3Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC
4Epidemiology and Surveillance Research Department, American Cancer Society, Atlanta, GA
5Department of Neurology, Massachusetts General Hospital, Boston, MA
email: Alberto Ascherio (
[email protected])
*Correspondence to Alberto Ascherio, Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115
Funded by:
Michael J. Fox Foundation
Kinetic Foundation
National Institute of Environmental Health Sciences; Grant Number: ES10804
Abstract:Objective
Chronic, low-dose exposure to pesticides is suspected to increase the risk for Parkinson's disease (PD), but data are inconclusive.
Methods
We prospectively examined whether individuals exposed to pesticides have higher risk for PD than those not exposed. The study population comprised participants in the Cancer Prevention Study II Nutrition Cohort, a longitudinal investigation of US men and women initiated in 1992 by the American Cancer Society. Follow-up surveys were conducted in 1997, 1999, and 2001. The 143,325 individuals who returned the 2001 survey and did not have a diagnosis or symptoms of PD at baseline (1992) were included in the analyses.
Results
Exposure to pesticides was reported by 7,864 participants (5.7%), including 1,956 farmers, ranchers, or fishermen. Individuals exposed to pesticides had a 70% higher incidence of PD than those not exposed (adjusted relative risk, 1.7; 95% confidence interval, 1.2-2.3; p = 0.002). The relative risk for pesticide exposure was similar in farmers and nonfarmers. No relation was found between risk for PD and exposure to asbestos, chemical/acids/solvents, coal or stone dust, or eight other occupational exposures.
Interpretation
These data support the hypothesis that exposure to pesticides may increase risk for PD. Future studies should seek to identify the specific chemicals responsible for this association. Ann Neurol 2006
Received: 25 January 2006; Accepted: 28 April 2006