Fluoride in drinking water linked with impaired childhood cognition: Study

London  (the Uttam Hindu): Exposure to fluoride during the foetal stage or early childhood may impair cognition in children, a new study has warned. Published in the journal Environmental Health Perspectives, the study from Karolinska Institutet in Sweden now supports a few previous studies indicating that exposure to fluoride during the foetal stage or early childhood is not good for kids. Elevated concentrations of fluoride can occur in well water, and in some countries, it is added to drinking water to counteract caries in the population. Fluoride occurs naturally as fluoride ions in drinking water, but the concentrations are generally low in public water supplies. In some countries, such as the US, Canada, Chile, Australia and Ireland, fluoride is commonly added to the municipal water supply at around 0.7 mg per litre to prevent caries. “Given the concern about health risks, the addition of fluoride to drinking water is controversial and has been widely debated in the USA and Canada,” said Maria Kippler, associate professor at the Institute of Environmental Medicine, Karolinska Institutet. “Our results support the hypothesis that even relatively low concentrations of fluoride can impact children’s early development,” she mentioned. The researchers followed 500 mothers and their children in rural Bangladesh, where fluoride occurs naturally in the drinking water, to investigate the association between early exposure to fluoride and children’s cognitive abilities.

The concentrations are similar to those found in many other countries worldwide. The exposure to fluoride in the mothers and children was determined by measuring the concentrations in urine samples, which reflects ongoing exposure to all sources, such as drinking water, food and dental care products. “I’d like to stress that dental care products such as toothpaste are not normally a significant source of exposure since they are not intended for ingestion,” said Dr Kippler. Fluoride in toothpaste is important for prevention of caries, but it’s important to encourage small children not to swallow the toothpaste during brushing. The median concentration of fluoride in urine of the pregnant Bangladeshi women was 0.63 mg/L. Children that had more than 0.72 mg/L fluoride in their urine by the age of ten also had lower cognitive abilities than children with less fluoride in their urine, with most pronounced associations for verbal reasoning skills and the ability to interpret and process sensory input. It is important to assess the overall results of several similar longitudinal studies, according to the researchers.