An unexpected toxin was recently found to have a strong association with intellectual ability in children — manganese. Where is this manganese coming from? Surprisingly, from tap water that contains manganese concentrations below the current guidelines for safety. Kids with the most exposure to manganese through tap water were found to have lower IQs than those children who were not exposed.
Workplace manganese exposure has been known to have neurotoxic effect, but this is the first study to look at lower concentrations of manganese from drinking water and food sources and its effects on cognitive function.
Manganese is a naturally occurring toxin found in soils in certain regions, which can then leach into groundwater sources. This is especially true in parts of Canada where this study took place. Hopefully more studies will be done and awareness will be raised about filtering this toxic element out of our drinking water.