A chara, – For clarification, the terms of reference of Irish Expert Body on Fluorides and Health (IEBFH) remain as those given to it by the Minister for Health (Letters, July 31st-August 8th). These are to oversee the implementation of the recommendations of the Forum on Fluoridation, to advise the Minister and evaluate ongoing research – including new emerging issues – on all aspects of fluoride, its delivery methods as an established health technology and as required, and to report to the Minister on matters of concern at his/her request or on own initiative.
In your Letters pages, reference has been made to a review carried out by a team led by Dr Choi from Harvard University of a number of studies, mainly from China, which claim to show a very small effect of very high and possibly very low levels of naturally occurring fluoride on children’s intelligence. The Expert Body assessed these studies in 2011 and found that they were of no relevance to the national Irish water fluoridation schemes. The data from these studies, if taken at face value, would indicate that the highest IQ levels were associated with water fluoride ranges similar to those used in water fluoridation schemes in Ireland. However, the overall design of these studies is poor and they do not provide evidence of any effect on intelligence from either high or low fluoride levels. This view was also shared by the European Union’s Scientific Committee on Health and Environmental Health (SCHER) in late 2011 which was similarly critical of the quality of the studies involved.
The Choi paper expressed a view that the potential effects of very high fluoride levels should be further investigated. This might be a more relevant question in countries with high naturally occurring fluoride, including the United States, which has an upper legal limit for naturally occurring fluoride in water of 4mg/L, which is five times higher than the maximum Irish legal limit for water fluoridation schemes. The Choi paper did not claim to have found any evidence of harm associated with water fluoridation.
Studies in Ireland and worldwide have found that water fluoridation has a significant benefit for dental health among both children and adults which is additional to the benefits of using fluoridated toothpastes and other products. People residing in fluoridated areas have better teeth with less disease than those residing in non-fluoridated areas. For example, in the last all-Ireland survey, there was in the order of 40 per cent fewer cavities in children living in fluoridated areas. Better dental health means better overall health, with fewer oral infections. The impact of poor dental health can be significant, particularly in the case of young children, where treatment might involve the use of hospital general anaesthetic services.
Fluoridated toothpastes became available in Ireland in the early 1970s and the proportion of toothpastes sold containing fluoride gradually increased over that decade. Today, over 90 per cent of toothpastes sold contain fluoride. Prior to the widespread availability of fluoride toothpaste, studies conducted in Dublin city (fluoridated 1964) and Cork city (fluoridated 1965) indicated that fluoridated water was having a major impact in reducing dental decay levels in children. Studies conducted elsewhere including in the United States and Britain showed similar results.
The safety and benefits of fluoridation have been endorsed by major international organisations such as the World Health Organization, the Center for Disease Control and Prevention (US), the United States Public Health Service, the United States Surgeon General, the Federation Dentaire Internationale/World Dental Federation, the International Association for Dental Research and the Royal College of Physicians of England. One of the principal findings of the Forum on Fluoridation report in Ireland (2002) was that the best available and most reliable scientific evidence indicates that at the maximum permitted level of fluoride in drinking water at 1 part per million, human health is not adversely affected. To date, no new studies have emerged which change this finding.
The Expert Body continues to monitor all aspects of fluoridation in Ireland. A more comprehensive up-to-date statement on fluoridation is on the Irish Expert Body on Fluorides and Health website fluoridesandhealth.ie– Is mise,
Dr SEAMUS O’HICKEY,
Irish Expert Body on Fluorides
Fenian Street, Dublin 2.