Neurobehavioral effects of long-term exposure to pesticides: results from the 4-year follow-up of the PHYTONER study.

Laboratoire Santé Travail Environnement, EA 3672, Institut de Santé Publique d'Epidémiologie et de Développement, 146 rue Léo Saignat, 33076 Bordeaux cedex, France.
Occupational and environmental medicine (Impact Factor: 3.23). 02/2011; 68(2):108-15. DOI: 10.1136/oem.2009.047811
Source: PubMed

ABSTRACT The aim of the PHYTONER study is to investigate the role of pesticides on neurobehavioral performances in French vineyard workers.
929 workers affiliated to the health insurance system for farmers in the Bordeaux area of south-western France were enrolled in the study in 1997-1998. They were contacted for a first follow-up in 2001-2003. Participants completed a questionnaire and nine neurobehavioral tests. They were classified according to their life-long pesticide exposure, as directly exposed, indirectly exposed or non-exposed. Educational level, age, sex, alcohol consumption, smoking, psychotropic drug use and depressive symptoms were taken into account in the analysis.
614 subjects were available for investigation at follow-up. Follow-up analysis confirmed that the risk of obtaining a low performance on the tests was higher in exposed subjects, with ORs ranging from 1.35 to 5.60. Evolution of performances over the follow-up period demonstrated that exposed subjects had the worst decreases in performance. The risk of having a two-point lower score on the Mini-Mental State Examination was 2.15 (95% CI 1.18 to 3.94) in exposed subjects.
These results suggest long-term cognitive effects of chronic exposure to pesticides and raise the issue of the risk of evolution towards dementia. The PHYTONER study is the first to provide prospective data on the natural history of neurological disorders associated with pesticide exposure.

1 Bookmark
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A possible link between pesticide exposure and Parkinson's disease has been postulated for many years and recent studies help clarify this association. Mark Greener reports.
    Progress in Neurology and Psychiatry 01/2013; 17(1).
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The intensive use of pesticides has attracted great attention from the Chinese government. However, current regulations have had limited influence on their safe use. Although the acute neurologic effects of pesticides have been well documented, little is known about their cumulative effects. Knowledge of the impact of pesticides on health may convince farmers to minimize their use. We conducted a cross-sectional study in three provinces of China to evaluate the relationship between pesticide exposure and neurological dysfunction. Crop farmers were divided into two groups depending on their level of pesticide exposure. A total of 236 participants were assessed by questionnaire and neurological examination for symptoms and signs of neuropathy. Characteristics of neurologic dysfunction following cumulative low-level exposure were assessed with logistic regression analysis. Farmers exposed to high-level pesticide use had greater risk of developing sensations of numbness or prickling (odds ratio (OR) 2.62, 95% confidence interval (CI): 1.08-6.36). After adjusting for recent exposure, the risk of numbness or prickling symptoms (OR 2.55, 95% CI: 1.04-6.25) remained statistically significant. Loss of muscle strength and decreased deep tendon reflexes had OR > 2, however, this did not reach statistical significance. These findings suggest that overuse of pesticides increased risk of neurologic dysfunction among farmers, with somatosensory small fibers most likely affected. Measures that are more efficient should be taken to curb excessive use of pesticides.
    International Journal of Environmental Research and Public Health 04/2014; 11(4):3995-4006. · 1.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Given the neurotoxic properties of pesticides, suggested by experimental results and clinical observations, many epidemiological studies have investigated neurological effects following acute or chronic exposure to pesticides. This review provides an overview of current knowledge about pesticide effects on the central nervous system: neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis), cognitive disorders, and psychiatric disorders (mood disorders, anxiety, depression and suicide).ResultsParkinson's disease, the most widely studied in relation with pesticide exposure, particularly with insecticides and herbicides, was observed to be a risk factor of the disease. Evidence is scarce for Alzheimer's disease and amyotrophic lateral sclerosis, but quite consistent. Cognitive and psychiatric disorders were often observed in relation with organophosphate insecticide exposure. Cognitive disorders were found associated with acute and chronic exposures, and psychiatric disorders mostly with poisonings. These epidemiologic studies were limited by a lack of detailed and reliable exposure assessment. The role of genetic susceptibilities has been recently observed, but must be further investigated.RésuméPosition du problèmeAu vu des propriétés neurotoxiques de certains pesticides, observées expérimentalement ou lors de manifestations cliniques, de nombreuses études épidémiologiques se sont penchées sur les effets neurologiques en lien avec une exposition aiguë ou chronique à de telles substances. Nous proposons ici une revue de la littérature épidémiologique sur les troubles cognitifs, les maladies neurodégénératives (maladie de Parkinson, maladie d’Alzheimer et sclérose latérale amyotrophique), et les troubles psychiatriques (troubles de l’humeur, anxiété, dépression et suicide).RésultatsL’exposition aux pesticides a été beaucoup étudiée en lien avec la maladie de Parkinson, plus particulièrement l’exposition aux insecticides et aux herbicides, qui se sont révélés être des facteurs de risque de la maladie. Pour la maladie d’Alzheimer et la sclérose latérale amyotrophique, les arguments en faveur d’un tel lien sont moins nombreux, mais sont relativement cohérents. Les troubles cognitifs et psychiatriques ont été très souvent observés dans le contexte d’une exposition aux insecticides organophosphorés. Les troubles cognitifs ont été retrouvés associés à des expositions aiguës ou chroniques, et les troubles psychiatriques principalement aux intoxications. La plupart des études épidémiologiques restent en partie insuffisantes du fait d’une mesure de l’exposition limitée ou peu fiable. L’existence de susceptibilités génétiques a récemment été observée, ouvrant la voie à de nouvelles perspectives de recherche pour mieux comprendre la relation entre pesticides et troubles neurologiques.
    Revue d Épidémiologie et de Santé Publique 10/2012; 60(5):389–400. · 0.66 Impact Factor