According to researchers, children living in cities with pollutants concentration above US standards, including fine particulate matter, have a high risk of brain inflammation and degenerative changes later in life, including Alzheimer’s and Parkinson’s disease.
The study found that children who were healthy, lived in highly polluted environment, and carry the gene apolipoprotein e4 allele – known to increase a person’s risk for Alzheimer’s disease – showed diminished cognitive responses compared with children that carry the gene apolipoprotein e3 allele.
Metropolitan Mexico City has serious environmental pollution, and is home to more than 8 million children who are exposed to high levels of fine particulate matter in the air every day since birth, researchers say.
In the study, researchers created two groups of children in Mexico City based on several variables, such as age, gender, socio-economic status and education, and several others. Children in these groups that carried the e4 allele were compared with children that carried the e3 allele and found that those with e4 allele had three significant changes.
They had short-term memory shortfalls, an IQ that while within the normal limits measured 10 points less, and changes in key metabolites in the brain that mirror those of people with Alzheimer’s disease.
“The results add to growing data suggesting e4 carriers could have a higher risk of developing early Alzheimer’s disease if they reside in a polluted urban environment,” said Dr Lilian Calderon-Garciduenas from the University of Montana.
She added that the study raises concerns about important educational issues. With Mexico City children mostly attend under-privileged public schools, they do not build cognitive reserves that serve as a defense to pollution impacts.
“An IQ difference of 10 points will likely have a negative impact on academic and social issues, including bullying and teen delinquency,” she said.
The study was published in the Journal of Alzheimer’s Disease.