9 April, 2021
Concern for regional water supplies.
REGIONAL Queensland towns are battling with water discolouration and there are growing concerns on the human health effects of Manganese (Mn) in drinking water, with bottle-fed babies and pregnant mothers facing the highest risk, according to CQUniversity researchers.
CQUniversity water expert Dr Adam Rose said “if you are pregnant, I would recommend using bottled water, at least until Mn levels have reduced”.
“And if you are currently bottle-feeding your infant, I would recommend using bottled water, as the combination of tap water high in Mn and the additional Mn found in baby formula has the potential to expose the young one to increased levels of Mn,” Dr Rose said.
Dr Rose explained recent research had shown that increased levels of Mn in the system contributed to impacts on pregnant women, infant size and mortality, and intellectual function in children and the elderly.
“The primary source of Mn in natural catchments in the surrounding soils, bedrock and organic matter washed into the water bodies that end up increasing the levels in our regional water supplies,” he said.
“Traditionally, Mn has been limited to an aesthetic concern – at about this time every year residents notice their water coming out of taps that is somewhat discoloured and doesn’t look pleasing to drink. We are told it is safe to do so – but is it?”
Dr Rose said while Mn was an essential trace element used in bone formation and in amino acid, lipid, and carbohydrate metabolism in humans, too high a level could prove dangerous.
“Chronic exposure to Mn in drinking water at concentrations below the health-based guidelines used in many countries may result in neurological disorders similar to a Parkinson’s-like disease called ‘Manganism’,” he said.
“Along with neurological disorders, modest Mn concentrations in drinking water have also been linked with increased dental caries, behavioural problems, reduced intelligence quotient (IQ) scores, difficulty with mathematics and reduced motor skills in children.”
Dr Rose said the treatment of water containing increased Mn concentrations could be difficult, as Mn took much longer to oxidise and precipitate compared with other metals such as iron.
“Given the challenges of effective and efficient Mn treatment removal, understanding the temporal and spatial relationships of Mn will be invaluable in assisting water managers to refine or customise treatment options,” he said.
“For example, an early forewarning of increased Mn may signal the need to add additional steps in the treatment process, as a measure to effectively remove Mn from the water.
“This is particularly the case in the context of smaller treatment plants, where resources may be limited, and communities do not have ready access to alternate supplies in the event of water contamination with Mn resulting in discolouration.”
Dr Rose said it remained unclear as to whether or not short-term increases in Mn concentrations could contribute significantly to long-term exposure from drinking water, particularly when age-specific drinking water intake was considered.
He said this problem, and many others were predicted to become more frequent under climate change scenarios.
“For regional Queensland to ensure safe drinking water supplies into the future we need to start to rehabilitate our regional water cycles,” Dr Rose said.
“The only weapon we have in regional Queensland for our fight against climate change is water, so the solution is simple – we need to slow the flow and give back our rivers some H20.”