An Evaluation of Water Fluoridation Levels in Ireland, 1995-2004

In the Republic of Ireland fluoridation of public water supplies (range 0.8-1.0ppm fluoride) is mandatory and commenced in 1964. Approximately 73% of the population received fluoridated water from 733 monitored public water supplies in 2004. Drinking water quality regulations based on Irish and European Union legislation require testing of fluoride levels in water supplies on a daily and monthly basis. Objectives: The aim of this study was to analyse the test results of fluoride levels in public water supplies for the period 1995-2004 to determine the levels of compliance in Ireland. Methods: The monthly test results from all public water supplies between 1995 and 2004 were analysed. These results were categorised as 'Exceedances'(>1.00ppm) or 'Compliance'(1.00ppm or less) and the 'Exceedances' were than further analysed in the categories A (<1.05ppm), B (1.05<1.25ppm), C (1.25<1.5ppm) or D (>1.5ppm). Results: The results of the levels of compliance with the Drinking Water Regulations demonstrated that the levels of compliance range from 87.7% in 1995 to 96.1% in 2004. The breakdown of the exceedances for the same period showed that the vast majority of the exceedances were in category A and B and that the proportion decrease over the time period examined. Between 0.07% and 0.32% of the exceedances were in category D. Conclusion: These results indicate that there were high levels of compliance with the Drinking Water Regulations in the period 1995-2004. Exceedances dropped over the reported period and the majority of results were in the lower rang of exceedances (i.e. category A and B). The results suggest the need to consider an 'Acceptable Control Range' with targets for the proportion of tests within defined limits, along with agreed range of accuracy and operational targets for fluoridation in water treatment plants instead of the current narrow range of the statutory limits for water fluoridation.