title: Effects of manganese exposure on visuoperception and visual memory in schoolchildren.
abstract: Manganese (Mn) is an essential metal involved in multiple physiological functions. Environmental exposure to airborne Mn is associated with neurocognitive deficits in humans. Children, whose nervous system is in development, are particularly susceptible to Mn neurotoxicity.
  
  
  
  The objective of this study was to assess the association between Mn environmental exposure, and effects on visuoperception and visual memory in schoolchildren.
  
  
  
  We assessed schoolchildren between 7 and 11 years old, with similar socioeconomic status, from the mining district of Molango (n=148) and Agua Blanca (n=119, non-mining area) in Hidalgo state, Mexico. The Rey-Osterrieth Complex Figure (ROCF) test was used to assess visuoperception and short-term visual memory. Hair manganese (MnH) concentrations were determined. Linear regression models were constructed to estimate the associations between MnH and ROCF scores, adjusted for potential confounders.
  
  
  
  The geometric mean MnH was nine times higher in schoolchildren from the Mn mining area (5.25μg/g) than in schoolchildren from the non-mining area (0.55μg/g). For the ROCF Copy trial, MnH was significantly associated with an increase in distortion errors (tangency, closure), angle errors, overtracing (partial overtracing). In the Immediate Recall trial, MnH was significantly associated with increased overtracing (partial overtracing) and omissions, and negatively associated with the number of perceptual drawn units, total score and percentage immediate recall.
  
  
  
  MnH is associated with alterations in visuoperception and short-term visual memory in schoolchildren exposed to airborne Mn.
authors.affiliation: National Institute of Public Health, Environmental Health Department, Cuernavaca, Morelos, CP 62100, Mexico. Electronic address: david.hernandez@insp.mx.
authors.forename: D
authors.initials: D
authors.lastname: Hernández-Bonilla
authors.affiliation: National Institute of Public Health, Environmental Health Department, Cuernavaca, Morelos, CP 62100, Mexico. Electronic address: mescamilla@insp.mx.
authors.forename: C
authors.initials: C
authors.lastname: Escamilla-Núñez
authors.affiliation: Centre for Interdisciplinary Research on Health and Well-being, Society and Environment (CINBIOSE), Université du Québec à Montréal, Montreal, Canada. Electronic address: mergler.donna@uqam.ca.
authors.forename: D
authors.initials: D
authors.lastname: Mergler
authors.affiliation: National Institute of Public Health, Environmental Health Department, Cuernavaca, Morelos, CP 62100, Mexico. Electronic address: lrodriguez@insp.mx.
authors.forename: S
authors.initials: S
authors.lastname: Rodríguez-Dozal
authors.affiliation: National Institute of Public Health, Environmental Health Department, Cuernavaca, Morelos, CP 62100, Mexico. Electronic address: cmarlene@insp.mx.
authors.forename: M
authors.initials: M
authors.lastname: Cortez-Lugo
authors.affiliation: National Institute of Neurology and Neurosurgery, Neurochemistry Department, Manuel Velasco Suárez, Mexico City, CP 14269, Mexico. Electronic address: montesergio@yahoo.com.
authors.forename: S
authors.initials: S
authors.lastname: Montes
authors.affiliation: National Institute of Neurology and Neurosurgery, Neurochemistry Department, Manuel Velasco Suárez, Mexico City, CP 14269, Mexico. Electronic address: carbolit2001@yahoo.com.mx.
authors.forename: L A
authors.initials: LA
authors.lastname: Tristán-López
authors.affiliation: National Institute of Respiratory Diseases, Clinical Epidemiology Department, Mexico City, CP 14080, Mexico. Electronic address: mininvest2001@yahoo.com.mx.
authors.forename: M
authors.initials: M
authors.lastname: Catalán-Vázquez
authors.affiliation: National Institute of Public Health, Environmental Health Department, Cuernavaca, Morelos, CP 62100, Mexico. Electronic address: aschilmann@insp.mx.
authors.forename: A
authors.initials: A
authors.lastname: Schilmann
authors.affiliation: National Institute of Public Health, Environmental Health Department, Cuernavaca, Morelos, CP 62100, Mexico. Electronic address: hriojas@insp.mx.
authors.forename: Horacio
authors.initials: H
authors.lastname: Riojas-Rodriguez
mesh_terms: D002648:Child; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008345:Manganese / Q000097:blood / Q000633:toxicity*; D008570:Memory, Short-Term / Q000187:drug effects*; D008800:Mexico / Q000453:epidemiology; D008906:Mining; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects; D012189:Retrospective Studies; D014796:Visual Perception / Q000187:drug effects*
chemical_list: D008345:Manganese
keywords: Manganese; Neurotoxicity; Schoolchildren; Visual memory; Visuoperception