Ecogenetics of Parkinson's Disease: Prevalence and Environmental Aspects in Rural Areas

Abstract

ABSTRACT:We make use of the unique combination of a homogeneous genetic and racial origin in the rural population of Quebec and the facilities of free and universal access to medical care, to study the distribution of the prevalence of Parkinson's disease in the 9 rural hydrographic regions of the Province. Through 3 different methods of ascertainment, confirmed by two control probes, we demonstrate that the prevalence of Parkinson's disease is of uneven distribution within rural areas. We further investigated the characteristics of the regions of high prevalence. These regions which are predominantly agricultural and areas of intensive market gardening were also the areas with the highest use of pesticides. RESUME: Ecogenetiquede la maladie de Parkinson: prevalence et aspectsenvironnementaux dans les regions rurales Nous avons tire profit d'une combinaison unique de facteurs presents dans la population rurale du Quebec, soit une population dont I'origine genetique et raciale est homogene et un acces gratuit et universel aux soins m6dicaux, pour fitudier la distribution de la prevalance de la maladie de Parkinson dans 9 regions hydrographiques rurales de cette province. Nous d6montrons, a I'aide de 3 methodes differentes de reperage des cas, confirmees par 2 sondes de controle, que la prevalence de la maladie de Parkinson est inegale au sein des regions rurales. Nous avons etudi6 plus attentivement les caracteristiques des regions de haute prevalence. Comme ces regions sont agricoles et servent a la culture maraichere intensive, elles sont egalement celles qui utilisent le plus de pesticides.

Epidemiology and etiology of Parkinson’s disease: a review of the evidence

“…An ecological study reported high prevalence of PD in rural agricultural regions in Canada [282]. In case reports, parkinsonism was attributed to different pesticides [283][284][285][286][287][288].…”

“…Beside the Canadian prevalence study [282], other prevalence studies [335][336][337] and an incidence study [338] reported higher occurrence of PD in rural than in urban areas. However, one study found lower prevalence of PD among farmers [339] and another study found slightly higher incidence in urban than in rural areas [52].…”

Poor hydroxylator phenotypes of debrisoquine and S‐mephenytoin are not over‐represented in a group of patients with Parkinson's disease [letter]

“…Subsequently they postulated that the prevalence of PD might also vary in relation to environmental factors, and that the greater use of pesticides in rural areas might lead to a greater prevalence of PD (Barbeau et al, 1987). Paraquat is structurally similar to MPP+, the toxic metabolite of 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP) (Barbeau et al, 1985b;Snyder & D'Amato, 1985) which produces a Parkinsonian syndrome in man (Davis et al, 1979;Langston et al, 1983).…”

Herbicides and the Risk of Neurodegenerative Disease

“…PD risk is also associated with different -but related -environmental factors such as rural living, farming and drinking well water. Studies have shown higher occurrence of PD in rural versus urban areas in Canada (Barbeau et al, 1987), the United States (Lee et al, 2002), and Denmark (Tuchsen et al, 2000). Drinking well water is a risk factor for PD (Tsai et al, 2002); however, this tends to be dependent on rural living, so the two factors are interrelated (Koller et al, 1990).…”