Preparatory work for the update of the tolerable upper intake levels for manganese

This technical report describes collection and appraisal of scientific evidence that could be used to derive an upper intake level (UL) for manganese. Two systematic reviews were conducted assess the relationship between ‘high’ manganese oral exposure neurological effects in i) humans (all life-stages) ii) animals (mammals). Other sources described though narrative reviews. For two 14,471 records screened at title abstract resulting 49 human 63 animal studies being included after full text screening. adults 19 children reporting on outcomes judged suitable establishing UL assessed risk bias, while all bias. Due lack addressing same comparable manner was considered too scarce perform meta-analyses. Evidence from also not meta-analyses given large heterogeneity study design. The provided some adverse association drinking water intelligence quotient (IQ) children. reported effect size significant associations range 2 4 lower IQ points per 10-fold increase concentrations water. Animal more consistent neurodevelopment relatively high doses compared exposures. Animals exposed during early life found sensitive Mn neurodevelopmental effects.