A new study has shown that people who are exposed to higher concentrations of small airborne particulates such as from diesel exhaust or other traffic-related air pollutants are more likely to be detected with high levels of amyloid accumulation and tau build-up in the brain, which are key indicators for Alzheimer’s disease. The findings suggest that fine particulate matter from diesel exhaust and traffic-related air pollution impacts the volume of amyloid plaque in the brain. The study broadly reveals how air pollution impacts each organ in the body. The adverse effect of air pollution on lungs and respiratory health is quite known but the impact of air pollution on the brain and Alzheimer’s disease is less acknowledged.
The authors of the study assessed brain tissue contributed by 224 people who lost their lives at a median age of 76. They linked the frequency of Alzheimer’s markers identified in the brains of participants with recognized air pollution exposure in areas where they lived. The study found that individuals who inhaled the highest levels of fine-particulate air pollution categorized as pollutant particles fewer than 2.5 microns in diameter were more likely to be diagnosed with greater levels of amyloid accumulation in their brains. The authors of the study say that when people inhale higher concentrations of small airborne particulates, they surpass the blood-brain barrier and enter the brain. These particles are poisonous and as they reach the brain they can lead to significant damage.
Experts found that participants who were exposed to one microgram per cubic meter (1 µg/m3) greater than average in the year prior to their death were two times increased risk of having higher levels of plaques in the brain. People with elevated exposure in the three years prior to their death were at 87 percent increased risk of having greater levels of tau buildup. The findings showed that the robust link between air pollution and amyloid plaques was seen in those people without the gene variant known as APOE e4, which is linked to Alzheimer’s risk. It shows that ecological factors like air pollution might be a contributing factor to Alzheimer’s disease in patients whose genetics are not linked to the disease.
