Fluoridation of Tap Water
In September 2001 the Department of Health legislated regulations in respect of fluoridation of potable water in South Africa. Fluoridating potable water is considered by some as being unconstitutional in that the use of fluoridated water is forced on consumers who have no choice in the matter. During the past 5 years water boards, and Rand Water in particular, made several submissions to the appropriate ministries. A key aspect of these submissions is that Rand Water sought indemnity from the Department of Health against any claims arising from the fluoridation of water that may give rise to possible health implications or impact on the environment or industrial water users. Fluoride, in the correct concentration, is effective in protecting teeth and is especially necessary in children within the 1 to 10 year age group.
The rationale for supplementing potable water with fluoride is that South Africans, particularly those in rural areas who do not use fluoridated toothpaste, would benefit. Given that most people in rural areas do not receive piped water the benefit will not reach the target population. Furthermore only 0,65 % of the water produced by Rand Water is used for drinking purposes. This equates to 19 000 m3 of the 3 000 000 m3 sold daily, which means that 99,35% or R25 000 of the direct costs (chemical costs per day) is not effectively utilised for the intended purpose. The question thus arises, how cost effective is this method of augmenting dietary fluoride intake? Rand Water will introduce 1 500 kg of fluoride daily into potable water. Approximately 1000kg of fluoride per day will find its way into water streams.
This may have long-term negative consequences on the water environment. The cost of de-fluoridation can amount to as much as R5.50/m3 if reverse osmosis is used and the cost of using alternative methods of removing fluoride from water such as the use of activated aluminia is estimated at R1.80 m3 Who will be expected to pay this cost? Rand Water does not consider fluoridation of water as the highest priority for South Africa. In fact, the total estimated national cost of R30 million per annum should rather be used to extend the provision of free water to South Africans. Based on Rand Water’s experience the R30 million could extend water provision to some 300 000 unserved consumers. Considering the above costs and the large sector of the targeted population, that will not be reached through water fluoridation, the question raised is whether alternative methods of fluoride augmentation such as supplementing milk, sugar, salt, maize meal have been thoroughly investigated.
These may have a much better chance of reaching the target population, especially if fluoridated foods are subsidised such that it is cheaper than non-fluoridated foods. Rand Water does not wish to challenge the rationale for augmenting diets with fluoride. Rand Water does however express major concerns with the decision to fluoridate potable water. It is apparent, from the above, that the social and financial viability of fluoridating potable water supplies requires further consideration. It is therefore proposed that government reconsider the matter of fluoridating potable water supplies and that other options are investigated. In the meanwhile, Rand Water will abide by the regulations regarding fluoridation.
1. Background and introduction
The Department of Health has legislated regulations indicating that water service providers are obliged to fluoridate water to a concentration level of up to 0,7 mg F-/l as of September 2002.
Fluoridation of water supplies has always been, and will remain a highly controversial and an emotional issue. The anti-fluoridation lobby views it as forced medication with several perceived health risks, the public at large do not seem to have a specific opinion while the dental fraternity supports fluoridation due to its prophylaxis value in respect of the control of dental caries. This communication is aimed at conveying a synoptic overview of Rand Water’s position on the issue of fluoridation of potable water.
Fluoride is an essential trace element of a normal diet and is required from birth until permanent teeth have been formed as it is incorporated in the tooth enamel, which is formed before the teeth erupt. Fluoride is therefore essential for the development of resistance to caries and the benefit is life long. Fluoride, present in the saliva is considered a further benefit due to its continued bathing of the teeth, which further provides protection against dental caries.
Studying the contents of the University of York document (NHS Centre for reviews and Dissemination Report 18 Fluoridation of drinking water) the range of the mean difference in the proportion (%) of caries–free children is 5.0 to 64 %, with a median of 14.6 % (Inter-quartile range 5.0-22.1 %). The American Dental Association refers to studies by Murray JJ (1993) and Newbury E (1989), which list caries reduction at 50 – 59 % and 15 – 35 % in adults respectively. The question is raised how successful is fluoridation really and whose information is correct?
The degree of caries reduction after the implementation of water fluoridation would largely depend on the dietary habits of the community investigated. Underprivileged communities with unbalanced diets, containing very little if any fluoride, stand to gain the most by fluoride augmentation. In affluent areas, where fluoride toothpaste is used and fluoride augmentation in children’s diets is practised via tablets, water fluoridation may show very little improvement.
Results obtained from an extensive literature study indicate that there is no evidence that fluoride concentration levels in potable water up to a concentration level of 1 mg F-/l could have any detrimental affect on healthy adults weighing 70 kilograms and consuming 2 l of water per day over a period of 70 years. It should, however, be noted that the impact of all chemical substances are related to age, weight and the physical health of a person. One of the problem areas is that the range of fluoride levels that is beneficial to health is narrow in that 0,5mg F-/l is considered the minimum concentration required for protection against dental caries whereas mild dental fluorosis can begin at levels above 1 mg F-/l.
Dental fluorosis occurs as a result of exposure to excess levels of fluoride during the period of calcification of teeth up to 10 years of age. Fluorosis relates to the uptake of excess amounts of fluorine into the system. This may have a variety of health implications on man, which is related to the amount of fluorides consumed. Mild dental fluorosis is evident within a small percentage of population at 1mg F-/l and Skeletal fluorosis results from fluoride intake above 20 mg F-/l.
One of the concerns regarding fluoridation of water supplies is the fact that fluoride is both a chronic and an acute poison. The probable acute toxic dose has been estimated at 4 mg F-/kg for a young child, 15 mg F-/kg for an older child and 32 mg F-/kg for adults.
Diseases implicated by the anti-fluoridation groups include skeletal fluorosis and carcinogenicity, depressed thyroid activity, kidney damage and interference with the immune system. It should, however, be noted that there is an enormous amount of contradicting information in literature, both in respect of the benefits and the health threats of fluoridated water supplies.
The concentration levels stated to have health implications are generally much higher than those recommended for water supplies. To date there is no conclusive evidence that any of the above health implications will occur at the targeted fluoride concentration levels of 0,7 – 1,0 mg/l.
2. Estimated costs of water fluoridation to Rand Water
For the purpose of this report capital cost estimates are based on a study conducted during 1996 for five different water fluoridation plants for The Metropolitan Water District of Southern California. The treatment capacity of these plants varies from 123 500 to 2 850 000 m3of water per day and the required fluoride dosage was estimated at 0,6 mg/l. For all practical purposes the size and dosages required are comparable to what would be envisaged for Rand Water.
The capital cost required to treat 1 000 m3 per day would be R 3 695. The estimated capital cost for a fully automated state of the art fluoridation dosing plant for Rand Water would then be:
Vereeniging Water Treatment Plant : R 4 850 000
Zuikerbosch Water Treatment Plant: R 14 000 000
Total: R 18 850 000
The capital amount takes into account the following components: 20 % for Planning and Design, 10 % for Contract Administration and 15 % for Contingencies.
Capital redemption at 13,47 % per annum for 20 years is calculated at R 3 298 700 per year, which equates to 0,30 cent per m3 of water treated.
Irrespective of the type of fluoride compound that will be used, a team of highly trained operators will have to be employed to operate several dosing sites and to oversee the offloading, storage and distribution of the concentrated product (as well as operating the dosing plant). Additional staff will have to be trained to deal with emergencies that could arise after spillage or contamination. All concentrated fluoride compounds are toxic and extreme care must be exercised during handling such compounds. This fact cannot be over emphasised and the design of storage and handling facilities must incorporate all the required safety aspects.
The minimum number of personnel required per site would be:
· Four dedicated shift operators to monitor the performance of the dosing plants
· Three operators to receive and distribute the product to the various dosing plant
· One senior operator to supervise the fluoridation of water. The total annual remuneration for these personnel is estimated at R 1 322 000 which equates to 0,12 cent per m3 of water treated.
Maintenance costs on the fluoridation plant are expected to be high due to the highly dangerous and corrosive nature of the product. Annual maintenance cost is estimated at 5 % of the capital cost, this is estimated at R950 000 which equates to 0,1 cent per m3 of water treated.
Based on the above assumptions the annual cost of fluoridation to Rand
Water would be:
· Item Value Cost in cents per m3
· Capital redemption R 3 298 700 0,30
· Chemical treatment cost R 9 351 000 0,85
· Personnel R 322 000 0,12
· Plant maintenance R 950 000 0,10
Total R14 921 750 1,37
The present fluoride concentration in both the raw water used for purification and the water put into supply varies within the range of 0,18 to 0,2 mg F-/l. To meet the 0,7 mg F-/l required by the new legislation it would require Rand Water to increase the concentration level of fluorides in its potable water supply by an average of 0,5 - 0,6 mg F-/l.
Based on the above information the estimated cost in respect of fluoridation is 1.37c/ m3.
Based on the latter, the following calculations were done for a 3000 000 m3/day plant (rounded off):
Total costs per day = R41 000
Total costs per annum = R15 million
When meeting basic water needs of 25 l per person/day this will result in an increase in costs to the consumer of 13c per person/annum and for the average household usage of 30 m3/month, which will result in an increase of R4.93 per household/annum.
3. Estimated costs of Water fluoridation to South Africa
It is estimated that the total volume of water treated by Water Boards, Metropolitan Councils and the larger Local Authorities as provided for under the new water fluoridation Act is 6 000 000 m3/day. Based on the assumptions made above, the estimated cost of fluoridation to the country is estimated at:
Total cost per day R82 000
Total costs per annum R30 million
4. Impact of water fluoridation on the environment
The present cost of de-fluoridation of water can amount to as much as R5.50/m3 if reverse osmosis is used. Alternative methods of removing fluoride from water such as the use of activated aluminia is estimated at R1.80 m3. A question that has not been adequately addressed is who will be expected to pay these costs should it become necessary to remove fluorides? Rand Water will dose 1 500 kg of fluoride per day in order to meet the required standard of 0,7 mg/l of fluoride. However, of the 1 500 kg per day only 9,8 kg will be used by Rand Water’s consumers for drinking purposes.
Considering other consumptive uses, it is estimated that 1 000 kg of fluoride introduced into the water will not be used consumptively and will find its way back into the environment.
The Target Water Quality Range (TWQR) for the aquatic environment listed in the South African Water Quality Guidelines (Volume 7 Aquatic Ecosystems –1996 page 70) is shown in the next table.
· TWQR and criteria Fluoride in mg/l
· Target water quality range =< 0.75
· Chronic Effect Value 1,500
· Acute Effect Value 2,540
Generally the environment is tolerant to fluorides and little impact has been seen at fluoride concentration levels below 2 mg/l.
High fluoride concentrations may be harmful in certain industries, particularly those involved in the production of food, beverages, pharmaceuticals and medical items. Fluorides in boiler feed water also present problems in steam generation plants and need to be removed prior to use. The disposal of mineralised wastewater from steam generation plants with high fluoride concentrations may become a problem in future. The present fluoride effluent standard is set at 1 mg F-/l and this value has also been used as in-stream water quality standards in newly established river forums.
As water is a scarce commodity in South Africa it is recycled and this should be considered in the overall water use strategy. Fluoridation of Rand Water’s supply at a rate of 0,5 mg F-/l will introduce 365 tons of fluoride per annum into the environment.
If 0,5 mg F-/l is added to our water supply this would theoretically imply (during periods of drought or the dry season) that the effluent concentrations will also increase by 0,5 mg F-/l as fluorides are not appreciably removed through the wastewater treatment process. This for example could increase the average fluoride concentration in the effluent emanating from a works near Alberton to approximately 0,9 mg F-/l which is only 0,1 mg F-/l less than receiving water quality criteria.
This may start presenting a problem to both the receiving streams and the downstream users if not managed with care. The fluoride levels in other works investigated were much lower and would therefore not present a problem.
A study of the present in-stream fluoride concentrations of the major streams and water bodies that will receive water emanating from wastewater treatment works treating water supplied by Rand Water was conducted. The fluoride concentration in most of these streams varies between 0.3 and 0,4 mg F-/l and would therefore have to be monitored carefully once fluoridation is implemented. Of concern is the high average fluoride values recorded for the Rietspruit (Loch Vaal) and the Vaal River downstream of the Barrage at Lindeques Drift.
Fluoride concentrations in these streams at times will exceed the 1 mg F-/l level if the water supplied by Rand Water is augmented by 0,5 mg F-/l, especially during the dry seasons or periods of drought. The question is raised, to what extent Rand Water will be held liable if down-steam users are required to de-fluoridate in order to comply with set standards. If it is the intention to manage fluoride concentrations in potable water to levels below 0,7, mg F-/l it will be necessary to protect the raw water supplies of down-stream users. It will therefore be necessary to consider existing in-stream fluoride concentrations when establishing Rand Water’s dosage rates.
5. Alternative forms of fluoridation
Only 0,65 % (19000 m3) of the 3 000 000 m3 of potable water sold daily by Rand Water is consumed by humans. This equates to 19 000 m3 of the 3 000 000 m3 sold daily, which means that effectively 99,3 % or R25 500 of the direct costs (chemical costs per day) is not effectively utilised for the intended purpose. Is the cost of water fluoridation not too high for a developing country like South Africa and is this affordable in view of the recently implemented free water scheme and the many unserved people who still need to be accommodated.
Various alternative means of supplementing daily fluoride requirements should be considered including options such as milk and salt. These alternatives are possible and have been implemented in several countries. Of the 25 countries investigated by Heath et al (1995) 13 fluoridated water supplies, 7 domestic salt and 5 milk. Six countries namely Sweden, The Netherlands, Belgium, West Germany and Hungary discontinued fluoridation while Austria, Denmark, France Italy and Greece have never introduced fluoridation.
Two alternative supplementation options being considered by some researchers are sugar and flour, but information is still incomplete at this stage. Fluoridating maize-meal is another option that could be considered, as it is a staple food to a large sector of our population. It is also this sector that often does not receive piped water, having to rely on streams, wells and boreholes for their water supply. Fluoridating municipal supplies would therefore be of little benefit to this sector.
6.1. Only 0,65% of Rand Water’s supply to 10 million consumers is used for drinking purposes. Therefore fluoride added to 99,35% of potable water will be wasted insofar as the value of fluoride is concerned.
6.2. The mandatory introduction of water fluoridation will cost water consumers in South Africa approximately R30 million per annum.
6.3. In spite of consumers paying R30 million per annum fluoridated water will not reach all the target population since most people in rural areas do not receive piped water.
6.4. Rand Water will introduce 1 500 kg of fluoride daily into potable water. Approximately 1 000kg of fluoride per day will find its way into water streams. This may have long-term negative consequences on the water environment.
6.5. Alternative options as a means of augmenting diets of South Africans with fluoride require rigorous consideration. Examples of alternative options include supplementation of salt, maize meal, sugar and milk.
6.6. Any consumer claims regarding possible health implications or impact on the environment, as a consequence of water fluoridation, will be referred to the Department of Health.
6.7. An inadequate level of public debate has occurred on the matter of fluoridation. It is recommended that the extent of debate be increased.
6.8. In the meanwhile, Rand Water will abide by the regulations regarding fluoridation. To this end Rand Water has notified all local authorities to which it supplies drinking water of its intentions to comply with the relevant legislation promulgated in September 2000, which stipulates the procedures that should be followed. Rand Water has submitted registration documentation required by the Department of Health and has established a technical committee to investigate implementation of fluoridation