Study links common agricultural pesticides to Parkinson’s disease
May 15, 2009
Parkinson’s disease is the most common neurodegenerative movement disorder in the US. The disease affects approximately 1 percent of all people over the age of 65. Rates of Parkinson’s disease appear higher among farmers and rural residents, leading to speculation that pesticides might play a role in development of the disease.
A recent study conducted in California’s Central Valley found that people who live within 500 meters of a field sprayed with the pesticides maneb and paraquat in combination had a 75 percent higher risk of Parkinson’s disease relative to controls.
This is the second study to evaluate associations between exposure to a combination of pesticides and the risk of Parkinson’s disease. These results add to the growing literature suggesting that exposure to multiple chemicals may be more harmful than exposure to individual chemicals and contribute to the debate of evaluating chemical safety one at a time rather than in combination.
Paraquat and maneb are among the top 25 most commonly used agricultural pesticides in California. More than one million pounds of each compound is applied annually in the state.
Paraquat is commonly used to kill weeds in agricultural fields, while maneb is used to control fungi in soil. Both pesticides are often used on the same food crops, including potatoes, beans and tomatoes. Exposure to both compounds at the same time is not unusual.
Homes and other residential exposures, not work-related exposures, were the focus of the study. People living near farm fields where the pesticides are used can be exposed to the chemicals via wind and dust.