Environmental manganese exposure and associations with memory, executive functions, and hyperactivity in Brazilian children

• Published in: Neurotoxicology (Park Forest South) 2018-12, Vol.69, p.253-259
• Main Authors: Carvalho, Chrissie Ferreira de, Oulhote, Youssef, Martorelli, Marina, Carvalho, Carla Oliveira de, Menezes-Filho, José Antônio, Argollo, Nayara, Abreu, Neander
• Format: Article
• Language: English
• Subjects: Brazil - epidemiology; Child; Child psychology; Children; Cognitive ability; Cognitive development; Correlation analysis; Cross-Sectional Studies; Environmental Exposure; Executive function; Executive Function - drug effects; Executive Function - physiology; Exposure; Female; Ferromanganese; Hair; Human exposure; Humans; Hyperactivity; Hyperkinesis - chemically induced; Hyperkinesis - diagnosis; Hyperkinesis - epidemiology; Interference; Male; Manganese; Manganese - adverse effects; Manganese compounds; Memory; Memory - drug effects; Memory - physiology; Recall; Verbal Learning - drug effects; Verbal Learning - physiology; Verbal memory
• ISSN: 0161-813X; 1872-9711
• DOI: 10.1016/j.neuro.2018.02.002

•We report associations between hair Mn concentrations and neuropsychological performance and hyperactivity behavior in children.•Long-term airborne Mn exposure may be associated with lower neuropsychological performance in children.•Elevated concentrations of MnH were associated with lower verbal memory. Manganese (Mn) is an essential element, however high levels of Mn have been associated with lower neuropsychological performance and behavioral problems in children. We investigated the associations between hair Mn concentrations and neuropsychological and behavioral performances among children with long-term exposure to airborne Mn aged between 7 and 12 years. Neuropsychological performance included tests of: verbal memory, inhibitory control, cognitive flexibility, verbal fluency, and motor function. We used the Conners Abbreviated Rating Scale for teachers to assess students’ behaviors of hyperactivity. Hair manganese (MnH) concentrations in children and exposure to airborne manganese from a ferro-manganese alloy plant were analyzed and correlated with tests scores. Multivariable linear models adjusting for potential confounders showed that elevated levels of MnH were associated with lower performance in verbal memory, as measured by the free recall after interference (β = – 1.8; 95% CI: – 3.4, – 0.2), which indicates susceptibility to interference, and Delayed Effect (β = –2.0; 95% CI: –3.7, – 0.2), representing a loss of information over time. Additionally, we found patterns of effect modification by sex in three subtests measuring verbal memory: the free recall after interference score, Interference Effect, and Delayed Effect (all at p