Those living near fields where pesticides are sprayed are 75% more likely to develop Parkinson’s disease. In a new study from the University of California (UCLA), researchers report that strong evidence points to an association between the neurodegenerative disorder and pesticides.

Parkinson’s disease is a chronic, progressive neurological disorder, typically affecting motor skills and speech. It is the second most common neurodegenerative disease, affecting more than 1 per 1000 people in Europe. Although Parkinson’s is most common in the over 60s, many people are diagnosed in their 40s and younger - whilst not fatal, complications arising from the disease can be deadly. Researchers know that pesticides - specifically maneb, a fungicide and the herbicide paraquat - cause Parkinson’s-like symptoms in animals. This recent UCLA study provides the first evidence for a similar process in humans.

In this new epidemiological study of Central Valley residents who have been diagnosed with Parkinson’s disease, researchers found that years of exposure to the combination of maneb and paraquat increased the risk of Parkinson’s by an average of 75%. For people under 60 diagnosed with Parkinson’s, earlier exposure had increased their risk for the disease by as much as four- to six-fold.

The study, published in the American Journal of Epidemiology and written by Beate Ritz, professor of epidemiology at the UCLA School of Public Health, and Sadie Costello, of the University of California, Berkeley, found that Central Valley residents who lived within 500 meters of fields sprayed between 1974 and 1999 had a 75% increased risk for Parkinson’s. The researchers enrolled 368 longtime residents diagnosed with Parkinson’s and 341 others as a control group.

In addition, people who were diagnosed with Parkinson’s at age 60 or younger were found to have been at much higher risk because they had been exposed to maneb, paraquat or both in combination between 1974 and 1989, years when they would have been children, teens or young adults.

Parkinson’s disease has oft been reported to occur at high rates among farmers and in rural populations, contributing to the hypothesis that agricultural pesticides may be partially responsible. However, until now, data on human exposure has been unavailable due to the difficulties in measuring individuals’ environmental exposure to specific pesticides. Of particular concern, and consistent with other theories regarding pesticides exposure and the progression of certain pathologies, is that the data suggests there to be a critical window of exposure that may have occurred years before the onset of Parkinson’s.

Every year over 200,000 tonnes of pesticides are released into the European environment. These chemicals can have harmful impacts on human adults and children.

Within the EU, the arrival of this latest research could not be more timely. New European rules on pesticides have been introduced required member states to produce National Action Plans (NAPs) for pesticide reduction because of concerns about serious health effects. HEAL, alongside a group of other NGOs state that this timetable for implementing the EU Directive and Regulation is too slow. We advocate for a maximum level of health protection against the adverse effects of pesticides use and exposure, particularly for children and other vulnerable groups. In the past six months HEAL have launched the ‘Sick of Pesticides’ campaign in France (with the Mouvement Pour le Droit et le Respect des Générations Futures) and the UK, aiming to increase public awareness of the dangers of pesticides and calling for an immediate reduction in pesticide use.