title: Motor function in adults of an Ohio community with environmental manganese exposure.
abstract: OBJECTIVE
  The objective of the present study was to evaluate motor function in order to assess the effects of long-term, low-level environmental manganese (Mn) exposure in residents of an Ohio community where a large ferro- and silico-Mn smelter has been active for more than 50 years.
  
  
  METHODS
  One hundred residents from the Mn-exposed Ohio community were evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS), a postural sway test, and a comprehensive questionnaire exploring demographics and general health. The results were compared to those of 90 residents from a demographically similar comparison town in Ohio. Mn exposure was assessed using modeled airborne Mn and blood Mn (Mn-B). The UPDRS was employed to evaluate parkinsonian motor features. Postural sway was measured using a CATSYS 2000 (Danish Product Development).
  
  
  RESULTS
  No significant difference between the exposed and comparison groups was evident as to Mn-B, demographics or major health outcomes. The risk of abnormal UPDRS performance using "Motor and Bradykinesia" criteria was increased in the Mn-exposed group after adjustment for potential confounders such as the presence of other neurotoxic metals, factors affecting susceptibility to Mn, potential factors influencing motor performance, and other possible demographic confounders. No participant was diagnosed with clinical manganism by neurological examination. After adjustment for various potential confounders, the Mn-exposed group showed significantly higher postural sway scores under eyes-open conditions than the comparison group.
  
  
  CONCLUSIONS
  Subclinical findings on the UPDRS and postural sway in the Mn-exposed group may possibly reflect early subtle effects of chronic low-level Mn exposure. However, the cross-sectional study design, the small to medium effect sizes, and the little biological plausibility are limiting the possibility of a causal relationship between the environmental Mn-air exposure and the early subclinical neurotoxic effects observed.
authors.affiliation: Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Dong-Gu, Ulsan, South Korea. yanghokm@nuri.net
authors.forename: Yangho
authors.initials: Y
authors.lastname: Kim
authors.forename: Rosemarie M
authors.initials: RM
authors.lastname: Bowler
authors.forename: Nadia
authors.initials: N
authors.lastname: Abdelouahab
authors.forename: Matthew
authors.initials: M
authors.lastname: Harris
authors.forename: Vihra
authors.initials: V
authors.lastname: Gocheva
authors.forename: Harry A
authors.initials: HA
authors.lastname: Roels
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008345:Manganese / Q000009:adverse effects; D020149:Manganese Poisoning / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D008875:Middle Aged; D009048:Motor Skills / Q000187:drug effects / Q000502:physiology; D019957:Motor Skills Disorders / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology*; D009820:Ohio / Q000453:epidemiology
chemical_list: D008345:Manganese