Calls for immediate action to protect people from pesticides as study finds the risk of Parkinson’s disease 70 % higher for those exposed to pesticides

A prospective study of over 143,000 people has found that those who reported exposure to pesticides had a 70 percent higher incidence of Parkinson's disease.

The study published in the July issue of Annals of Neurology, a journal published by John Wiley & Sons, led the authors of the study to conclude that “The findings support the hypothesis that exposure to pesticides is a risk factor for Parkinson’s disease.”

Background information to the article states, “While the causes of Parkinson’s disease are not fully known, many studies have suggested that factors other than inherited genes play a large role. Data suggests that chronic exposure to pesticides, even in low doses, could be a risk factor.”

To examine this association, researchers led by Alberto Ascherio, M.D., Dr.PH of the Harvard School of Public Health conducted a prospective study of Parkinson's disease among a large cohort of Americans.

They included male and female participants of the Cancer Prevention Study II Nutrition Cohort who, beginning in 1982, completed extensive lifestyle questionnaires that included questions about occupation and exposure to pesticides and other potentially harmful materials. The researchers focused their study on 143,325 individuals who completed a follow-up survey in 2001, responded to a question about lifetime occurrence of Parkinson's disease, and had no symptoms at baseline.

The researchers requested the medical records of all study participants who reported a new diagnosis of Parkinson's disease after 1992 – that is 10 or more years after the reported exposure to pesticides -- to independently confirm the diagnosis. 413 cases were included in this study, and statistical analyses were performed to determine the association between pesticide exposure and Parkinson's disease.

The study found that the risk of Parkinson's disease was 70 percent higher for people exposed to pesticides.

Notably, a similar increase in risk was observed among people who were exposed because of their occupation, such as farmers, as among people not occupationally exposed, suggesting that home or garden use of pesticides, as well as other exposure groups, (ie. such as resident and bystander exposure), is also deleterious.

Background information to the article points out that because of its prospective design, the study provides much stronger evidence on a link between exposure to pesticides and Parkinson's disease than that so far available. Further, it states that, “…the results are in accordance with studies in experimental animals that have shown that compounds commonly used as pesticides can cause dopaminergic degeneration and motor abnormalities.”

Georgina Downs of UK Pesticides Campaign (www.pesticidescampaign.co.uk) the leading campaign highlighting the adverse health and environmental effects of pesticides, particularly for people in rural areas states, “Considering many pesticides are neurotoxic (toxic to the nervous system) then it isn’t surprising that study after study has found associations with various chronic neurological and neuro-degenerative diseases such as Parkinson’s. The findings of this study show the increase in risk in both occupationally exposed and non-occupationally exposed groups. This is highly significant in relation to the long-term exposure of rural residents and communities living near sprayed fields, where they can be repeatedly and frequently exposed to mixtures (“cocktails”) of pesticides, throughout every year and in many cases for decades.”

The Government are due to respond to last year’s report by the Royal Commission on Environmental Pollution (RCEP) entitled “Crop Spraying and the Health of Residents and Bystanders,” before the end of July 2006.

The RCEP report concluded that crop-spraying is a potential health risk and that chronic illnesses and diseases reported by people in rural areas, including cancer, Parkinson’s and ME, could be associated with pesticide exposure.

The RCEP had been asked to examine the scientific evidence on which DEFRA had based its decision on the risks to people from crop-spraying, following the determined and relentless five year campaign by Ms. Downs, who has recently received a prestigious award in recognition of her campaigning efforts.

Ms. Downs states, “The UK Government and the EU must take immediate action, which is very long overdue, especially in relation to the protection of children and other vulnerable groups. The only way to protect public health and prevent any illnesses that could be associated with pesticides, both now and for future generations, is to avoid exposure altogether through the widespread adoption of truly sustainable non-chemical and natural methods, as an alternative to chemical pest control. This would obviously be more in line with the Government’s commitment to sustainable development, sustainable food and farming and sustainable communities, as the reliance on toxic chemicals designed to kill plants, insects or other forms of life cannot be classified as sustainable.”