Two types of chemical compounds found in household products harm the development of oligodendrocytes, a type of cell essential for brain maturation. Epidemiological data confirm that children exposed to higher levels of these compounds have a higher risk of having motor dysfunctions or special educational needs.
Pollutants harmful to oligodendrocytes are so-called quaternary compounds (found in disinfectants and personal hygiene products) and organophosphates (used as flame retardants in furniture, electronics and building materials), according to a research from the Case University of the Western Reserve in Cleveland (USA).
Researchers have focused on oligodendrocytes, the cells that provide myelin to neurons in the brain. The aim is to understand why neurodevelopmental disorders, such as autism spectrum disorder (ASD) or attention deficit hyperactivity disorder (ADHD), are on the rise. "Genetic factors are not sufficient to explain this increase", they point out in Nature Neuroscience, where they present the results today.
To identify environmental factors, they evaluated 1,823 polluting chemical compounds. They have analyzed its effects in cell cultures of oligodendrocytes that were in the process of formation. Among the analyzed substances, the most toxic for oligodendrocytes belong to the groups of quaternary compounds and organophosphates.
Researchers have exposed mice that were in developmental stages to these compounds. They have verified that pollutants cross the blood-brain barrier, access the brain and, once there, affect the development of the cortex, cerebellum, corpus callosum and hippocampus.
They have confirmed these harmful effects in human brain organoids. Finally, they have done an epidemiological study that has revealed that 99.4% of boys and girls between the ages of 3 and 11 in the US have a detectable organophosphate metabolite in their urine.
Organophosphates “are used as additives in construction materials, electronic devices and furniture, but they are not chemically integrated into the product; therefore, they can be released into the environment and cause human exposure through inhalation, skin absorption or hand-to-mouth contact", reports Paul Tesar, director of the research, to La Vanguardia.
Children with a higher level of exposure to organophosphates were twice as likely to have special educational needs than those with a lower level. For motor dysfunctions, the risk is multiplied by six. Both disorders depend on the correct development of oligodendrocytes, as the myelination of the brain influences memory, learning and motor functions.
With the results obtained so far, "we do not recommend that these chemical compounds be completely removed from our environment, since many fulfill important functions", declares Paul Tesar. "Before recommending behavioral changes to citizens, studies designed to investigate whether specific levels of exposure can initiate or exacerbate diseases are needed."
