Feasibility and costs of water fluoridation in remote Australian Aboriginal communities

BACKGROUND

Fluoridation of public water supplies remains the key potential strategy for prevention of dental caries. The water supplies of many remote Indigenous communities do not contain adequate levels of natural fluoride. The small and dispersed nature of communities presents challenges for the provision of fluoridation infrastructure and until recently smaller settlements were considered unfavourable for cost-effective water fluoridation. Technological advances in water treatment and fluoridation are resulting in new and more cost-effective water fluoridation options and recent cost analyses support water fluoridation for communities of less than 1,000 people.

METHODS

Small scale fluoridation plants were installed in two remote Northern Territory communities in early 2004. Fluoride levels in community water supplies were expected to be monitored by local staff and by a remote electronic system. Site visits were undertaken by project investigators at commissioning and approximately two years later. Interviews were conducted with key informants and documentation pertaining to costs of the plants and operational reports were reviewed.

RESULTS

The fluoridation plants were operational for about 80% of the trial period. A number of technical features that interfered with plant operation were identified and addressed though redesign. Management systems and the attitudes and capacity of operational staff also impacted on the effective functioning of the plants. Capital costs for the wider implementation of these plants in remote communities is estimated at about $US 94,000 with recurrent annual costs of $US 11,800 per unit.

CONCLUSION

Operational issues during the trial indicate the need for effective management systems, including policy and funding responsibility. Reliable manufacturers and suppliers of equipment should be identified and contractual agreements should provide for ongoing technical assistance. Water fluoridation units should be considered as a potential priority component of health related infrastructure in at least the larger remote Indigenous communities which have inadequate levels of natural fluoride and high levels of dental caries.

Investigations on activated alumina based domestic defluoridation units

Investigations were carried out on the defluoridation of fluoride-spiked ground water in domestic defluoridation units (DDU) with activated alumina (AA). Specific safe water yield (SSY) was determined as a function of AA amount and adsorbent depth. Reuse potential of exhausted AA was assessed by regenerating and reusing AA in multiple defluoridation cycles. High fluoride uptake capacity (FUC) from ground water matrix as well as retaining approximately 95% FUC up to five cycles showed the suitability of AA for defluoridation in DDU. SSY, liters of safe water/kg AA, was dependent on the AA amount and its depth. There was a significant decrease in SSY with the decrease in AA depth in different DDUs, even though the amount was maintained constant. The derived data from four DDUs, with 3-5 kg AA and depth ranging from 5 to 13 cm, showed that DDU design is one of the most important parameter to be considered for optimizing SSY.

Technical aspects of water fluoridation in the United States and an overview of fluoridation engineering world-wide

This paper summaries the technical aspects of water fluoridation in the United States, and gives an overview of the engineering aspects of water fluoridation world-wide. The status of water fluoridation in the USA is summarised. Fluoride chemicals used in the USA are discussed, as well as the equipment used to deliver these chemicals. A brief overview of fluoridation engineering world-wide is also presented.

Acute fluoride poisoning from a public water system

BACKGROUND

Acute fluoride poisoning produces a clinical syndrome characterized by nausea, vomiting, diarrhea, abdominal pain, and paresthesias. In May 1992, excess fluoride in one of two public water systems serving a village in Alaska caused an outbreak of acute fluoride poisoning.

METHODS

We surveyed residents, measured their urinary fluoride concentrations, and analyzed their serum-chemistry profiles. A case of fluoride poisoning was defined as an illness consisting of nausea, vomiting, diarrhea, abdominal pain, or numbness or tingling of the face or extremities that began between May 21 and 23.

RESULTS

Among 47 residents studied who drank water obtained on May 21, 22, or 23 from the implicated well, 43 (91 percent) had an illness that met the case definition, as compared with only 6 of 21 residents (29 percent) who drank water obtained from the implicated well at other times and 2 of 94 residents (2 percent) served by the other water system. We estimated that 296 people were poisoned; 1 person died. Four to five days after the outbreak, 10 of the 25 case patients who were tested, but none of the 15 control subjects, had elevated urinary fluoride concentrations. The case patients had elevated serum fluoride concentrations and other abnormalities consistent with fluoride poisoning, such as elevated serum lactate dehydrogenase and aspartate aminotransferase concentrations. The fluoride concentration of a water sample from the implicated well was 150 mg per liter, and that of a sample from the other system was 1.1 mg per liter. Failure to monitor and respond appropriately to elevated fluoride concentrations, an unreliable control system, and a mechanism that allowed fluoride concentrate to enter the well led to this outbreak.

CONCLUSIONS

Inspection of public water systems and monitoring of fluoride concentrations are needed to prevent outbreaks of fluoride poisoning.

Cost of fluoridation: 44 Florida communities

Previous data relating to the cost of fluoridation often do not include annualized costs or costs for labor and maintenance. The purpose of this study was to estimate accurately current costs for initiating and maintaining fluoridation and to develop a methodology that can be used to provide the cost basis for further cost-effectiveness studies. The data were collected from 44 Florida communities that had initiated community water fluoridation between 1981 and 1989. Equipment, installation, and engineering costs were derived from copies of actual invoices for equipment and services and then adjusted to 1988 dollars. The chemical costs were calculated from operational reports listing flow rate and pounds used. The cost was then adjusted according to whether the hydrofluosilicic acid was supplied as 15-gallon carboys, 55-gallon drums, in bulk, or as sodium silicofluoride or sodium fluoride. The initial cost was annualized at 2 percent and 4 percent over 15 years. Calculated operational costs included chemical costs, labor costs, and maintenance and repair costs. The operational costs were then added to the annualized depreciation costs and opportunity costs for the initial investment, to produce an estimated cost per person served. The total mean cost per person for all installations was $1.14 per year at 2 percent and $1.25 per year at 4 percent. The mean cost at 4 percent for communities of fewer than 10,000 was $2.12; for communities between 10,000 and 50,000 it was $0.68; and for communities over 50,000 it was $0.31. The total mean cost per person across all installations was $0.41 at 2 percent and 0.45 at 4 percent.(ABSTRACT TRUNCATED AT 250 WORDS)

The Venturi Fluoride Saturator project

This study was conducted to determine whether Venturi Fluoride Saturator (VFS) systems could be used to fluoridate small community and school water supply systems with an acceptable level of maintenance. VFS systems were installed and operated at four school and six community well sites according to state and federal regulations and recommendations. School VFS systems were unable to maintain optimum fluoride residuals even with substantial maintenance. All six community well site VFS systems performed acceptably, with only a few short lapses. VFS system maintenance was labor intensive. Recurring problems were caused by lengthy equipment delivery delays, the unavailability of timely technical assistance to support the VFS system, and the inadequate quality of VFS equipment and design. Based upon these findings, further expansion of the use of VFS systems either for community or school fluoridation cannot be recommended. Additional study of and improvements in the VFS system are indicated. Three major recommendations appear appropriate: (1) extensive laboratory testing of the VFS system concept under controlled conditions should be performed to determine the functioning parameters of this equipment under different hydrodynamic conditions; (2) additional research and development of the VFS unit to improve the quality of operations and the quality control of manufacturing and assembly should be undertaken; and (3) a VFS equipment distribution network should be developed, with sufficient logistical and technical support to supply equipment parts and expertise for installation, monitoring, and maintenance in a timely and efficient manner.

Acute fluoride poisoning associated with an on-site fluoridator in a Vermont elementary school

On August 30 1980, an outbreak of minor illnesses consisting of nausea and vomiting affected 22 individuals attending a farmers market at a school. Illness was associated with the consumption of beverages made from school water (Xc2 = 65.6, p less than .0001); analysis of the water showed high levels of fluoride (1,041 mg/l). The most likely source of the contamination was the school fluoridator, which had accidentally been left on continuous operation.

Groote Eylandt studies. 2. Fluoridation of a small domestic water supply, C.M.S. Angurugu mission, Groote Eylandt, N.T., Australia. 1973-1974

A system is described for fluoridation of a small community water supply. The design of the equipment is presented in relation to the requirements of a particular isolated region and in a basis for application to other similar areas. The problems found during the establishment of this system and their solution can be valuable as a guide for other communities.