A study has recently revealed that underground drinking water in parts of the U.S., Bangladesh, Cambodia, China may not be as safe as previously thought due to high level of manganese, especially at shallow depths, according to a study.
Manganese, a metal that is required by the body in tiny amounts, can be toxic at elevated levels, particularly in children. While groundwater can be contaminated with a number of heavy metals, more emphasis has been placed on assessing the levels of arsenic than manganese, although the latter also poses a threat to human health.
However, while arsenic contaminated wells should be avoided completely, manganese contaminated wells can be treated inexpensively or be used for agriculture rather than drinking water. According to studies, abnormal manganese concentrations in the brain to neurological disorders similar to Parkinson’s disease, and elevated levels in children may negatively impact neurodevelopment and cognitive performance.
They analysed chemical data from 16,000 wells in the Glacial Aquifer, the Ganges-Brahmaputra-Mehta Basin in Bangladesh, the Mekong Delta in Cambodia and the Yangtze River Basin of China. They studied the levels of arsenic and manganese at a range of depths, showing that, in general, arsenic levels increased with depth, while manganese levels decreased with depth.
The results showed that Glacial Aquifer were 9.3% contaminated when considering arsenic only; increased to 16.4% when considering arsenic and manganese. In Ganges-Brahmaputra-Mehta Basin (Bangladesh), 44.5% contaminated when considering arsenic only; increased to 70 percent when considering arsenic and manganese.
In Mekong Delta (Cambodia) there were 10% contaminated when considering arsenic only; increased to 32% when considering arsenic and manganese. In Yangtze River Basin (China), 19% contaminated when considering arsenic only; increased to 88% when considering arsenic and manganese.
Of the four regions, the Glacial Aquifer had the fewest contaminated wells. Lead researcher Samantha Ying said, “Providing access to safe drinking water is a global challenge that is increasing the demand for drinking water from underground sources,” Ying said. The research appears in the journal of Environmental Science & Technology.