Drinking water quality and health

We come to expect clean and healthy drinking water, but it is not pure as there are natural minerals in water depending on the source, and trace amounts of contaminants. There are also additives present which improve our drinking water. The natural mineral fluoride is present in many water supplies but is also added in some areas as it significantly reduces the risks of dental caries (decay) which require fillings and, potentially, causes tooth loss. There have also been concerns expressed about possible risks from fluoride and there is a duty under the Water Industry Act 1991 to conduct monitoring of health in fluoridated areas. This monitoring is undertaken by UK Health Security Agency on behalf of the Secretary of State for Health and Social Care. Within the framework of this monitoring UKHSA is, with the help of University of Leicester in the HPRU, contributing one specific project related to fluoride in water and child mental development. 

This project was prompted by some studies in other countries which have reported an association between exposure to high levels of fluoride during pregnancy and infancy, and reduced IQ measured in young children. Across England there is variation in water fluoride concentration, due to both natural variation and supplementary fluoride added to some supplies with very low natural fluoride, to bring it up to the target concentrations for dental protection. This study will assess whether or not there is any evidence in this population of an association between these varying fluoride levels in drinking water at the time of pregnancy of children in a national birth cohort, and IQ measured in these children.