A high concentration of fluoride in pregnant women in Mexico City is associated with high ADHD symptoms in school-age children, according to a study published today.
The study, led by Morteza Bashash of the University of Toronto, published in the latest issue of Environment International, was conducted with data from the 1994-2005 measurements of fluoride in the urine of 213 pregnant women in Mexico City.
The study, which also included researchers from the University of York (Canada), the National Institute of Public Health of Mexico and scientists from the United States, also analyzed the urine of children of 213 women aged 6 to 12 years.
After analyzing the levels of fluoride in children's urine and the results of the tests to measure their attention and hyperactivity, the researchers concluded that children with high exposure to this substance also showed greater symptoms of cognitive problems.
"Prenatal exposure to fluoride was more associated with behavioral problems with attention and concentration and cognitive problems, but not with hyperactivity," Dr. Bashash told Efe.
In a previous study published last year with the same group of mothers and children from Mexico City, researchers have already determined that prenatal exposure to high levels of fluoride has an adverse effect on children's IQ, says Informe21.
In Bash, he explained to Efe that although in Mexico the health authorities do not add fluoride to drinking water, as opposed to what is happening in Canada and the United States, in Latin America, the chemical is added to the salt used for cooking.
Fluoride has been added to water and food in many countries around the world for more than 60 years to prevent oral cavities.
But in recent years more and more scientists have warned the negative consequences of adding fluoride to drinking water especially for children's brain development.
ADHD is the most commonly diagnosed psychiatric disorder in children and affects 5 to 9% of all school-age children, according to data provided by the University of Toronto.