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 < 0.10). Overall, the results suggest that long-term airborne Mn exposure may be associated with lower performance in verbal memory, and hyperactivity behaviors.

锰（Mn）是必不可少的元素，但是高含量的Mn与儿童较低的神经心理表现和行为问题有关。我们调查了长期暴露于7至12岁的空气中锰的儿童中，头发中的锰含量与神经心理和行为表现之间的关联。神经心理学表现包括以下方面的测试：言语记忆，抑制性控制，认知柔韧性，言语流畅性和运动功能。我们使用Conners简短评定量表来评估教师的多动行为。分析儿童中的头发锰（MnH）浓度以及暴露于铁锰合金厂中的空气中的锰，并将其与测试成绩相关联。β  = – 1.8；95％CI：– 3.4，– 0.2），表示易受干扰，以及延迟效应（β  = –2.0； 95％CI：–3.7，– 0.2），表示信息随时间流逝。此外，我们在三个子测验中发现了通过性别改变效果的方式，这些测验测试了言语记忆：干扰得分后的自由召回，干扰效应和延迟效应（均在p  <0.10处）。总的来说，这些结果表明长期空气中锰的暴露可能与言语记忆能力下降和多动行为有关。