Metal exposure from industrial emission and neurotoxic effects on motor and olfactory functions in children and elderly

Background: Increased parkinsonism was observed in Valcamonica, a valley in the province of Brescia, Italy. Prevalence data were higher in the vicinities of ferroalloy plants that emitted manganese (Mn), lead (Pb), iron (Fe), copper (Cu) zinc (Zn), and chromium (Cr) for a century until 2001. The aim of this study was to assess motor and neurosensory functions in healthy adolescents and elderly residing in the impacted and reference area.  

Methods: Participants were recruited for neurobehavioral examination. Metals were measured in airborne particles collected with 24-hour personal samplers, tap water and soil at the participants’ homes. Biomarkers including blood, urine, and hair were collected for metal analysis. Independent covariates included gender, age, socio-economic status, parental education, body mass index, smoking and drinking habits.  

Results A total of 311 children and 255 elderly participated. Median airborne Mn was 31.4 ng/m3 in the exposed area and 24.7 ng/m3 in the reference area. Median soil Mn was 986 ppm in Valcamonica and 416 ppm in the reference area. Mn in blood, urine and hair were not significantly different between the two areas. Multivariate analyses showed an association between soil Mn and impairment of motor coordination and odor identification among the children, whereas motor and olfactory impairment were associated with airborne Mn among the elderly. Hair and blood Mn were both positively associated to increased tremor among adolescents  

Conclusions: Airborne environmental exposure to Mn is related to deficit in motor and olfactory functions in children and elderly.  Funding sources: EU 6thFP (contract no FOOD-CT-2006- 016253) and NIEHS Award N. R01ES019222.