- Parkinson’s disease. It appears that exposure to pesticides may trigger Parkinsons’s disease in genetically predisposed people. In a large 2006 study, researchers at Harvard School of Public Health found that participants exposed to pesticides (specifically, farmers, ranchers, fishermen and people who used pesticides in their homes or gardens) had a 70% higher incidence of Parkinson’s than those who weren’t exposed. The latest research, reported in February 2011 and conducted by the National Institute of Environmental Health Sciences, shows that people exposed in their professions to the pesticides paraquat or rotenone developed Parkinson’s approximately 2.5 times more often than people who were not exposed. Both pesticides cause cellular damage. Paraquat, in particular, is an extremely toxic substance originally developed as an herbicide.
- Dementia. A study that collected data between 1997 and 2003 from French vineyard workers who spent at least two decades applying pesticides to plants or working in buildings where pesticides were housed showed that these workers scored low on a test of memory and recall. Researchers speculate that the changes demonstrated in the mental functioning of these people indicate that they may eventually develop a neurodegenerative disease, such as Alzheimer’s.
- Infertility. In a 2008 review of studies on pesticide exposure, epidemiologists showed a decline in the semen quality and quantity of farm workers, which impaired male fertility by 40%. “Infertility, especially in men, is increasing in proportion to greater exposure to pesticides,” said Dr. Pimentel.
David Pimentel, PhD, professor, department of entomology, systematics and ecology, Cornell University, Ithaca, New York.