“…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).…”