If you were met with unappetizing discolored water over the summer and fall of 2013, you may be interested to know The Winnipeg Water and Waste Department recently released their Winnipeg Water Discoloration Investigation report done by CH2M HILL Canada Limited on the incidents. The water discoloration has been attributed to increased manganese and iron sediment being released into water circulation due to a change in suppliers of ferric chloride, a chemical used in water treatment. According to this report, the water is safe and meets all provincial and federal requirement for physical, microbiological and chemical standards (section 2 p1, Winnipeg Water Discoloration Investigation). It appears that manganese is safe to ingest and causes no ill health effects. but there are studies that we will discuss that raise some justified concerns. Furthermore, it is not clear what levels we have been exposed to, and even what levels of manganese in drinking water are acceptable. Here are a few common questions regarding manganese in our water:
What is manganese?
Manganese is a mineral element considered essential in the human body for proper functioning. In nature it is often found as a free element or in combination with iron and is used with phosphate in rust and corrosion prevention of metals. It can be lethal in very high doses.
What is the role of manganese in the human body?
In the human body manganese is essential in many enzyme systems like gluconeogenesis which helps regulate blood sugar. Manganese is required by the body to form and maintain bone, skin and gland function. The general recommended daily intake of manganese is between 2.5-5mg for adults and any excess manganese in the body is secreted by the gallbladder, liver and pancreas (World’s Healthiest Foods’s entry for manganese is an excellent resource for common foods rich in this mineral). Dr. Elanor Blaurock-Busch does an excellent job of outlining The Clinical Effects of Manganese is her article which includes deficiency symptoms, low level symptoms and increased level symptoms as well as information about toxicity.
Is it safe to drink?
CH2M HILL Canada Limited’s report states that the water is indeed safe to drink and meets all provincial and federal requirements. “The Guidelines for Canadian Water Quality identify a non-health based Aesthetic Objective for manganese at 0.05mg/L and this has been exceeded in some treated water and distribution system samples… elevated iron and manganese are not health concerns at the levels concerned” (Section 2 p1, Winnipeg Water Discoloration Investigation ). Winnipeg Regional Health Authority assures that these elevated levels over a short period of time do not have any adverse health effects and has published an article on the topic. Although this is very reassuring, it is important to note that there is some evidence of adverse effects of increased levels of manganese, especially in children. A University of Quebec study examined effects manganese on children’s cognition, motor skill and behavior whose homes where supplied with groundwater. Manganese consumption was estimated by testing the levels of minerals in the drinking water as well as a questionnaire that approximated the levels ingested in the diet. They discovered that:
“the average IQ of children whose tap water was in the upper 20% of manganese concentration was 6 points below children whose water contained little or no manganese. The analyses of the association between manganese in tap water and children’s IQ took into account various factors such as family income, maternal intelligence, maternal education, and the presence of other metals in the water.”
Although considered safe to drink, the City of Winnipeg recommends that residents not drink discoloured water.
At what level is manganese harmful?
There is little information about harmful levels of manganese in drinking water, so it is unclear at what levels manganese begins to have adverse health effects. It is suggested that adults should not exceed 11mg per day and this figure is lower for children and those with liver or pancreas disease as manganese is not as efficiently removed from the body. Symptoms of increased levels of manganese include neurological problems, tremors, mental confusion and anemia as manganese can interfere with the absorption of iron. Conversely, symptoms of low levels of manganese include impaired growth, infertility, uncontrolled blood sugar level, elevated blood pressure and pancreatic dysfunction (The Clinical Effect of Manganese, E. Blaurock-Busch, PhD).
What is being done to reduce the levels of manganese in our water?
For starters, the ferric chloride product will be changed to a chemical with lower levels of manganese and there will be a cleaning and inspection of three major water reservoirs. In addition to these measures there will be an ongoing measures to improve the water quality of the city of Winnipeg.
This article was prepared mainly for our own interest and should not serve as any type of guideline or resource. We do not have expertise in this area of public health, but we do have an interest in this topic, similar to most Winnipeg residents. If you’d like to contribute or if you feel we may be incorrect with some of our information presented, please do not hesitate to let us know.