Motor alterations associated with exposure to manganese in the environment in Mexico
Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Overexposure to manganese (Mn) causes neurotoxicity (a Parkinson-like syndrome) or psychiatric damage (“manganese
madness”). Several studies have shown alterations to motor and neural behavior associated with exposure to Mn in the
workplace. However, there are few studies on the effects of environmental exposure of whole populations. We studied the risk
of motor alterations in people living in a mining district in Mexico. We studied 288 individual people (168 women and 120
men) from eight communities at various distances from manganese extraction or processing facilities in the district of
Molango. We measured manganese concentrations in airborne particles, water, soil and crops and evaluated the possible routes
of Mn exposure. We also took samples of people's blood and determined their concentrations of Mn and lead (Pb). We used
“Esquema de Diagnóstico Neuropsicológico” Ardila and Ostrosky-Solís's neuropsychological battery to evaluate motor
functions. Concentrations of Mn in drinking water and maize grain were less than detection limits at most sampling sites.
Manganese extractable by DTPA in soils ranged between 6 and 280 mg kg−1 and means were largest close to Mn extraction
or processing facilities. Air Mn concentration ranged between 0.003 and 5.86 μg/m3; the mean value was 0.42 μg/m3 and
median was 0.10 μg/m3, the average value (geometric mean) resulted to be 0.13 μg/m3. Mean blood manganese concentration
was 10.16 μg/l, and geometric mean 9.44 μg/l, ranged between 5.0 and 31.0 μg/l. We found no association between
concentrations of Mn in blood and motor tests. There was a statistically significant association between Mn concentrations in
air and motor tests that assessed the coordination of two movements (OR 3.69; 95% CI 0.9, 15.13) and position changes in
hand movements (OR 3.09; CI 95% 1.07, 8.92). An association with tests evaluating conflictive reactions (task that explores
verbal regulations of movements) was also found (OR 2.30; CI 95% 1.00, 5.28). It seems from our results that people living close to the manganese mines and processing plants suffer from an incipient motor deficit, as a result of their inhaling
manganese-rich dust.
Description
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Journal Article (peer-reviewed)
item.page.format
Text
Keywords
MANGANESE, MEXICO, MINING, ENVIRONMENTAL EXPOSURE, MOTOR ALTERATIONS, NEUROTOXICITY, NEUROBEHAVIOURAL TESTING, MOTOR SKILLS, MOLANGO, MANGANESE POISOINING, NEUROBEHAVIOURAL MANIFESTATIONS, ENVIRONMENTAL HEALTH
Citation
DOI
Collections
IDRC Research Results / Résultats de recherches du CRDI
2000-2009 / Années 2000-2009
Environmental Pollution (includes SMEs and Mining) / Pollution de l’environnement (comprend les PME et l'industrie minière)
Latin America and the Caribbean / Amérique latine et Caraïbes
Research Results (Ecohealth) / Résultats de recherches (Écosanté)
2000-2009 / Années 2000-2009
Environmental Pollution (includes SMEs and Mining) / Pollution de l’environnement (comprend les PME et l'industrie minière)
Latin America and the Caribbean / Amérique latine et Caraïbes
Research Results (Ecohealth) / Résultats de recherches (Écosanté)