[Exposure to neurotoxic metals and prevalence of parkinsonian syndrome in the area of Brescia].
The prevalence of parkinsonian syndromes was studied in the province of Brescia (Northern Italy), in order to verify its possible increase in the surroundings of ferroalloy plants located in a valley of the pre-Alps. A case-list of subjects affected by these disturbances was identified using four different sources of information: a) registers from local medical clinics; b) admission charts from local hospitals; c) consumption of levodopa; d) NHS list of exemption from prescription payment, due to the illness. Exploratory data show a frequency of parkinsonian disturbances among the residents in the surroundings of the ferroalloy plants and downwind (crude prevalence = 358/100,000 population, standardized for age and sex = 438) significantly higher (s.m.r, = 1.58; C.I. = 1.41-1.76) than the entire Province (crude prevalence 246/100,000). This preliminary result could indicate the interaction of prolonged environmental exposure to heavy metals, such as manganese, and genetic factors, potentially relevant in this mountain population.