06:10pm Saturday 28 March 2020

Researchers suggest WHO re-evaluate drinking water guideline for manganese

In a recent commentary by an international team from The Hospital for Sick Children (SickKids), Norwich University and Better Life Laboratories, researchers identified more than 50 countries worldwide with drinking water or potential drinking water supplies exceeding the former recommended limit  for manganese  (400 micrograms per liter). The commentary, published online in February in Environmental Health Perspectives, suggests the WHO re-evaluate and re-instate its drinking water guideline for manganese.

Manganese is an essential nutrient, but in excessive quantities it has been linked to a variety of neurological problems in children and adults. These include learning disabilities, deficits in intellectual function, compulsive behaviours, emotional instability, hallucinations and attention disorders. It can be found in drinking water due to industrial pollution or naturally occurring geological deposits.

“Recent research suggests that the adverse health effects of manganese in drinking water are significantly greater than previously believed,” says Dr. Bibudhendra Sarkar, Senior Scientist Emeritus in the Molecular Structure & Function Program at SickKids. “These findings tell us that tens of millions of people may be drinking water with manganese over the former guideline of 400 micrograms/L. In fact, research suggests that this concentration may not be stringent enough to adequately protect public health.”

The WHO discontinued its drinking water guideline for manganese in 2011, stating that since the “health-based value [400 micrograms/L] is well above concentrations of manganese normally found in drinking-water, it is not considered necessary to derive a formal guideline value.” However, Sarkar and his team found that in Bangladesh alone, over 60,000,000 people are likely drinking water with manganese above the former guideline. The commentary demonstrates that the manganese concentration of drinking water in more than 50 countries is over the health-based value of 400 micrograms/L.

Sarkar and his team members Drs. Seth Frisbie and Erika Mitchell explain that for 53 years, manganese has been listed as a threat to drinking water, but only within the past ten years have the health risks, especially for children, of high concentrations of manganese been more thoroughly investigated.

“In light of the recent research, many scientists expected the WHO to revise its guideline to be more protective. The discontinuation of the guideline is extremely surprising,” says Sarkar.

Currently Health Canada does not have a health-based guideline for manganese so Canadians relied on the WHO guideline for health concerns related to manganese contaminated drinking water. With the discontinuation of the WHO guideline and the lack of a Health Canada health-based guideline, it is up to local governments and municipalities to set standards for protecting public health.

Drinking water with high levels of manganese has been found in Canada, and has been specifically studied in Quebec and New Brunswick. Since many studies of water quality did not test for manganese, the amount in Canadian drinking water is not well known.

“This commentary points out some of the recently published research that should be taken into account by the WHO when they prepared the 2011 revisions to their drinking water guidelines,” says Sarkar who is also Professor Emeritus at the University of Toronto. “My hope is that the WHO considers this research and eventually creates a new guideline with lower concentration recommendations than 400 micrograms/L.” 

Sarkar adds that without a WHO guideline for manganese, the scientific community needs to create a consensus of where manganese is present in drinking water, and what concentration of manganese should be considered unsafe for consumption.

This article was published by the U.S. National Institute of Environmental Health Sciences, National Institutes of Health, and Department of Health and Human Services.

About The Hospital for Sick Children
The Hospital for Sick Children (SickKids) is recognized as one of the world’s foremost paediatric health-care institutions and is Canada’s leading centre dedicated to advancing children’s health through the integration of patient care, research and education. Founded in 1875 and affiliated with the University of Toronto, SickKids is one of Canada’s most research-intensive hospitals and has generated discoveries that have helped children globally.  Its mission is to provide the best in complex and specialized family-centred care; pioneer scientific and clinical advancements; share expertise; foster an academic environment that nurtures health-care professionals; and champion an accessible, comprehensive and sustainable child health system.  SickKids is proud of its vision of Healthier Children. A Better World.™ For more information, please visit www.sickkids.ca

About SickKids Research & Learning Tower
SickKids Research & Learning Tower will bring together researchers from different scientific disciplines and a variety of clinical perspectives, to accelerate discoveries, new knowledge and their application to child health — a different concept from traditional research building designs.  The Tower will physically connect SickKids science, discovery and learning activities to its clinical operations.  Designed by award-winning architects Diamond + Schmitt Inc. and HDR Inc. with a goal to achieve LEED® Gold Certification for sustainable design, the Tower will create an architectural landmark as the eastern gateway to Toronto’s Discovery District.  SickKids Research & Learning Tower is funded by a grant from the Canada Foundation for Innovation and community support for the ongoing fundraising campaign. For more information, please visit www.buildsickkids.com.

For more information, please contact:

Matet Nebres
Manager, Media Relations
Communications and Public Affairs
The Hospital for Sick Children
Phone: 416-813-6380
Fax: 416-813-5328
email: [email protected]

Caitlin McNamee-Lamb
Communications Specialist
Communications and Public Affairs
The Hospital for Sick Children
Phone: 416-813-7654 ext. 1436
Fax: 416-813-5328
email: [email protected]

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