Air pollution particles link to distinct Alzheimer's markers

In an observational study of 340 cognitively unimpaired adults, researchers evaluated exposure to airborne particles and measured blood markers of Alzheimer's disease. They assessed particles with diameters up to 2.5 and 10 micrometres, alongside their manganese content and plasma levels of amyloid and phosphorylated tau proteins. Higher exposure to particles up to 2.5 micrometres was linked to a lower ratio of amyloid beta 42 to 40 in blood. Higher manganese within these fine particles was associated with higher levels of phosphorylated tau-181. Neither particles up to 10 micrometres nor their manganese content showed significant links with any measured biomarker. The link between fine particles and a higher tau-to-amyloid ratio appeared stronger in carriers of the APOE-ε4 gene variant.