The researchers have found that manganese levels have exceeded the guidelines in groundwater wells in Bangladesh, Cambodia, China, and the Glacial Aquifer, which covers 26 states in the northern US.
The group says that more emphasis is generally placed on the presence of arsenic than manganese. Furthermore, manganese is not even listed as a contaminant on the EPA's National Primary Drinking Water Regulations, which means levels aren’t monitored.
However, in recent times, the harmful effects of manganese have come into sharper focus with studies linking abnormal manganese concentrations in the brain to neurological ailments such as Parkinson’s disease and elevated concentrations of the material alleged to hamper the neurodevelopment and cognitive performance of children.
"Due to increasing knowledge on the detrimental impact of manganese on human health, particularly on children, manganese levels in these sources should be monitored more closely and governments should consider introducing manganese drinking water standards," says Samantha Ying, lead researcher.