Study Shows Certain Group Suffers More from Exposure to Air Pollution

A recent study conducted by researchers from various universities in the United States and Mexico have concluded that carriers of the apolipoprotein e4 allele gene (APOE4) showed significant decrements on attention and short-term memory when exposed to air pollutants (including PM 2.5) above the current USA standards. APOE4 is the most prevalent genetic risk factor for Alzheimer's disease. The estimated APOE4 gene in Caucasian population is 13.7%, while estimated population with Alzheimer's that carries the APOE4 gene is 36.7%. Study shows carriers of APOE4 gene have 10 to 30 times the risk of developing Alzheimer's disease by 75 years of age as compared to those not carrying the APOE4 gene. The combination of APOE4 gene and air pollution lead to the acceleration of neurodegenerative changes.

The study conducted in Mexico City, where 8 million children are involuntarily exposed to harmful concentrations of PM2.5 every day since conception showed children with APOE4 gene scored at least 10 IQ points below the average in verbal and full scale IQ tests. APOE4 children also had problems with odor detection (through the University of Pennsylvania Smell Identification Test) and failed to identify the smell of soap more than APOE3 carriers (APOE3 is considered the neutral genotype with an allele frequency of ~79% of the population).

In the United States alone, more than 200 million people live in areas where air pollution such as ozone and fine particulate matter (PM 2.5) exceeds the national standard. Significant associations have been found between exposure to particulate matter and increased mortality due to stroke, cardiovascular, and respiratory events.