The maximum acceptable concentration (MAC) for fluoride in
drinking water is 1.5 mg/L.
Low levels of fluoride occur naturally in most sources of drinking water
in Canada. Fluoride can occur naturally in surface waters from the deposition of particulates from the atmosphere and the
weathering of fluoride-containing rocks and soils, and in groundwater from leaching from rock formations. Fluoride is also
introduced in the environment by a variety of human activities such as chemical manufacturing plants and waste ponds; the
manufacture of aluminum, steel, glass, enamel, brick, tile, pottery, and cement; production of fluorinated chemical and phosphate
fertilizer; and metal casting, welding, and brazing.
Health Canada recently completed its review
of the health risks associated with fluoride in drinking water. This review assesses all identified human health risks, taking
into account new studies and approaches. Based on this review, the guideline for fluoride in drinking water is a Maximum Acceptable
Concentration of 1.5 mg/L.
Dental fluorosis is the most widely and frequently studied of all adverse effects of
fluoride. It is the effect occurring at the lowest level of fluoride exposure in the population. Mild and very mild dental
fluorosis are not considered to be adverse effects, whereas moderate dental fluorosis is found to be an adverse effect, based
on its potential cosmetic concern, and is used as the endpoint of concern in the risk assessment used to establish the Maximum
Acceptable Concentration. By protecting against a cosmetic effect of moderate dental fluorosis, Canadians are also protected
against the adverse health effects of severe dental fluorosis.
Skeletal fluorosis is the most serious adverse health
effect clearly associated with prolonged exposure to high levels of fluoride in drinking water. Skeletal fluorosis can occur
at very high exposure levels, and has rarely been documented in Canada.
The weight of evidence from all currently
available studies does not support a link between exposure to fluoride in drinking water at 1.5 mg/L and any adverse health
effects, including those related to cancer, immunotoxicity, reproductive/developmental toxicity, genotoxicity and/or neurotoxicity.
It also does not support a link between fluoride exposure and intelligence quotient deficit, as there are significant concerns
regarding the relevant studies, including quality, credibility, and methodological weaknesses.
Exposure
Major sources of exposure to fluoride are water, food and beverages, and dental products. Dental products contain
high levels of fluoride and can represent a very important source of exposure, particularly in young children who are more
likely to swallow toothpaste. Drinking water can be a significant source of exposure to fluoride; in 2005, community fluoridated
drinking water was provided to about 43% of Canadians. To a lesser extent, fluorides are also found in Canadian soils and
the atmosphere.
Treatment
Water containing fluoride levels greater than the MAC of 1.5 mg/L
can be treated at both municipal and residential scales through various approaches and technologies. At the municipal level,
options include blending of fluoride-rich waters with waters of low fluoride content, the selection of low-fluoride sources
and the removal of excess fluoride concentration by treatment processes at public water supply or household level. A wide
range of technologies, such as activated alumina, reverse osmosis, lime softening and ion exchange, are capable of reducing excess fluoride levels from drinking
water.
At the residential scale, reverse osmosis systems can be used at the point of use, and must be
capable of reducing the concentration of fluoride in water to a maximum of 1.5 mg/L to be certified. Distillation systems
installed at the point of use are effective to remove inorganic contaminants, including fluoride, and must be capable of reducing
fluoride levels to a maximum of 2.0 mg/L to be certified.
Link to Health Canada Guidelines on Fluoride - http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/2011-fluoride-fluorure/index-eng.php#i
Reverse Osmosis effective to reduce levels of fluoride 98% - http://www.evowater.ca/id58.html
Health Professionals Call for End to Water Fluoridation -
http://www.youtube.com/watch?v=yblka13FfCA
Doctor Exposes Fluoride as Poison - http://www.youtube.com/watch?v=xP7IPDfC3yg&feature=related
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Well Water Treatment, Fluoride, Reverse Osmosis, Ion Exchange, Water Purification NS
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