Could be, but no one knows. "a simple exposure to an environmental toxin is never enough to cause Parkinson’s. Most people exposed to a toxin do not develop the disease. In fact, there is no conclusive evidence that any environmental factor, alone, can be considered a cause of the disease." read more here http://www.pdf.org/en/causes

"Pesticide Exposure. Of all the chemical exposures that have been linked to Parkinson’s, pesticides have been reported the most consistently. Recent research has shown higher rates of Parkinson’s among people who were exposed to pesticides over a long period of time as part of their work. Investigating other types of pesticide exposure, such as home use, is more challenging. However, hobby gardening and home pesticide use have each been associated with PD in one report. Although few studies have identified specific pesticides as leading to PD, those that have been so identified include the insecticides rotenone and permethrin (used in clothing and mosquito netting to kill mosquitos); organochlorines such as beta-hexachlorocyclohexane (beta-HCH — used in the United States from the 1950s to the 1970s); and the herbicides paraquat and 2,4- dichlorophenoxyacetic acid (2,4-D). It is important to note that most people who are exposed to these pesticides do not go on to develop Parkinson’s. The herbicide 2,4-D is one of the chemicals making up Agent Orange, used as a defoliant during the Vietnam war era. Although Agent Orange has not been proven to cause PD, the US Department of Veterans Affairs has ruled that veterans with PD who served in Vietnam between January 9, 1962 and May 7, 1975 are eligible to receive disability compensation from the Veterans Administration."
http://www.pdf.org/environment_parkinsons_tanner