Note from FAN:  Because of what we learned from the results of the studies by Bashash et al. (2017) and Thomas et al. (2018) the most appropriate category for the Catfish study in NW England, is human experimentation. The study began in 2014 and is still ongoing.

Bashash et al. (2017) reported that prenatal exposure to fluoride resulted in a loss of up to 6 IQ points when the children were tested at age 4 and again between 6-12 years of age.

Thomas et al. presented the results of their study at a conference in March 2018. The researchers reported lower IQ scores due to prenatal fluoride exposure when the children were tested between the ages of 1 and 3.

•• See more about these studies here


Your child was born during a unique time in Cumbria, as water fluoridation was being reintroduced into certain areas of Cumbria by Public Health England. This created a once in a life time opportunity to look at the effects of fluoride in the water on children. We are running this study throughout all of Cumbria, comparing children’s teeth in West Cumbria, which has fluoridated water to other areas of Cumbria, which does not have fluoridated water. By comparing these areas we will be able to see the differences that water fluoridation makes to the oral health of the children living in these regions.We invited all children born in Cumbria between September 2014 and September 2015 to take part in this study. As your child grows we would like to follow up with some short questionnaires – initially every 6 months, then once a year, until their first year of school. These will ask questions about your child’s feeding practices and health.  We would also like to ask you some questions about your home and family.  We would like to examine their teeth when they are 3 years old, and again when they are 5 years old. All the information and data you give us will be kept confidential.You can look at participant information leaflets here:

CATFISH Study: Year 1 (2014/15)

CATFISH Study: Year 3 (2017/18)

If you have any questions please contact Michaela Goodwin or Laura MacKay on 0161 232 4704 or

*Online at