❓ Hon Giz Watson asks about the types, sources, quality, quantity, and calculation of fluoride used in WA's drinking water, and requests comparative tooth decay figures for fluoridated and non-fluoridated areas. The Minister for Health provides detailed answers regarding the chemicals used, their sources, quality standards, quantities added, calculation methods, and comparative tooth decay data.
AnsweredQoN 5205Legislative Council
QuestionView source ↗
I refer to fluoridation of drinking water in Western Australia, and I ask -
(1) What type or form of fluoride is used (for example: silicofluoride)?
(2) What is its source?
(3) What quality standard is required to be met for use in our drinking water and how is this assessed?
(4) What quantity is added to our drinking water?
(5) How is this quantity calculated and how does the calculation take into account fluoride obtained through other products (for example: food, beverages and dental products)?
(6) Will you please provide figures on tooth decay for areas in Western Australia with and without fluoridated drinking water that enable a comparison to be made?
(1) What type or form of fluoride is used (for example: silicofluoride)?
(2) What is its source?
(3) What quality standard is required to be met for use in our drinking water and how is this assessed?
(4) What quantity is added to our drinking water?
(5) How is this quantity calculated and how does the calculation take into account fluoride obtained through other products (for example: food, beverages and dental products)?
(6) Will you please provide figures on tooth decay for areas in Western Australia with and without fluoridated drinking water that enable a comparison to be made?
AnswerView source ↗
Answered
1 May 2012
Responded by
Minister for Mental Health representing the Minister for Health
Response time
56 days
(1) I am advised that the Water Corporation uses:
- Fluorosilicic acid (a compound of fluorine, hydrogen and silicon) for most fluoridated drinking water schemes in Western Australia (WA). The fluorosilicic acid is dosed into the water as a liquid, releasing fluoride which dissolves into the water.
- Sodium fluoride (a compound of fluorine and sodium) for some smaller drinking water schemes. The sodium fluoride is delivered as a powder and then dosed into the water, releasing fluoride which dissolves into the water.
- Sodium fluorosilicate (a compound of fluorine, hydrogen and silicon) for Derby. The sodium fluorosilicate is delivered as a powder then dosed into the water as a liquid, releasing fluoride which dissolves into the water.
(2) Fluorosilicic acid is sourced as a by-product from superphosphate production where phosphate rock and sulphuric acid are the main raw materials. This is the most common source of this product all over the world. The Water Corporation obtains most of this product from CSBP at Kwinana, with a smaller amount imported from New Zealand.
Sodium fluoride is produced by neutralizing hydrofluoric acid with soda ash or reacting sodium fluorosilicate with caustic soda or soda ash. The Water Corporation obtains most of this product from Orica and from Bisely and Co, on the east coast.
Sodium fluorosilicate is produced by neutralising sodium fluorosilicic acid with sodium chloride or caustic soda. The Water Corporation obtains this product from Redox Pty Ltd New South Wales.
(3) All chemicals added to drinking water must meet the quality standards specified in the "Australian Drinking Water Guidelines", as published by the National Health and Medical Research Council, as well as be approved by the Department of Health for addition to drinking water.
The Water Corporation also applies its own Strategic Product Specifications and monitoring programs to ensure that any product added to drinking water meets applicable levels of purity.
(4) The quantity varies across WA depending on climate, and is set to achieve the optimal level recommended by the statutory Fluoridation of Public Water Supplies Advisory Committee.
The optimal level across WA ranges from 0.6 to 0.9 milligram per litre, with a maximum of 1.0 milligram per litre established in law (the
Fluoridation of Public Water Supplies Act
1966).
The optimal level for Perth metropolitan area is 0.8 milligram per litre, with a range of 0.7 to 1.0 milligram per litre.
(5) The optimal fluoride level in water fluoridation programs is based on the methodology published by the National Health and Medical Research Council.
It is based on annual average maximum daily air temperature, and considers fluoride intake from other sources such as foods, drinks, dental products and the environment for all members of the community.
In general terms, the warmer the climate, the greater the water consumption and thus less fluoride is required in the water.
This is a standard methodology employed by health agencies across all jurisdictions in Australia.
(6) Data from the School Dental Service for 2010 shows that 6-year-old children in the non fluoridated Bunbury and Busselton areas had 35% more decay in their baby teeth, and 12-year-old children had nearly twice as much decay in their adult teeth, when compared with children of the same age in the rest of WA.
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- Fluorosilicic acid (a compound of fluorine, hydrogen and silicon) for most fluoridated drinking water schemes in Western Australia (WA). The fluorosilicic acid is dosed into the water as a liquid, releasing fluoride which dissolves into the water.
- Sodium fluoride (a compound of fluorine and sodium) for some smaller drinking water schemes. The sodium fluoride is delivered as a powder and then dosed into the water, releasing fluoride which dissolves into the water.
- Sodium fluorosilicate (a compound of fluorine, hydrogen and silicon) for Derby. The sodium fluorosilicate is delivered as a powder then dosed into the water as a liquid, releasing fluoride which dissolves into the water.
(2) Fluorosilicic acid is sourced as a by-product from superphosphate production where phosphate rock and sulphuric acid are the main raw materials. This is the most common source of this product all over the world. The Water Corporation obtains most of this product from CSBP at Kwinana, with a smaller amount imported from New Zealand.
Sodium fluoride is produced by neutralizing hydrofluoric acid with soda ash or reacting sodium fluorosilicate with caustic soda or soda ash. The Water Corporation obtains most of this product from Orica and from Bisely and Co, on the east coast.
Sodium fluorosilicate is produced by neutralising sodium fluorosilicic acid with sodium chloride or caustic soda. The Water Corporation obtains this product from Redox Pty Ltd New South Wales.
(3) All chemicals added to drinking water must meet the quality standards specified in the "Australian Drinking Water Guidelines", as published by the National Health and Medical Research Council, as well as be approved by the Department of Health for addition to drinking water.
The Water Corporation also applies its own Strategic Product Specifications and monitoring programs to ensure that any product added to drinking water meets applicable levels of purity.
(4) The quantity varies across WA depending on climate, and is set to achieve the optimal level recommended by the statutory Fluoridation of Public Water Supplies Advisory Committee.
The optimal level across WA ranges from 0.6 to 0.9 milligram per litre, with a maximum of 1.0 milligram per litre established in law (the
Fluoridation of Public Water Supplies Act
1966).
The optimal level for Perth metropolitan area is 0.8 milligram per litre, with a range of 0.7 to 1.0 milligram per litre.
(5) The optimal fluoride level in water fluoridation programs is based on the methodology published by the National Health and Medical Research Council.
It is based on annual average maximum daily air temperature, and considers fluoride intake from other sources such as foods, drinks, dental products and the environment for all members of the community.
In general terms, the warmer the climate, the greater the water consumption and thus less fluoride is required in the water.
This is a standard methodology employed by health agencies across all jurisdictions in Australia.
(6) Data from the School Dental Service for 2010 shows that 6-year-old children in the non fluoridated Bunbury and Busselton areas had 35% more decay in their baby teeth, and 12-year-old children had nearly twice as much decay in their adult teeth, when compared with children of the same age in the rest of WA.
Notice: This document is created or edited using unregistered or evaluation copy of rtLib valid for testing or development purposes only. To use it for productive or any other purposes please register it. You may purchase the license on
http://www.rtlib.com
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