Cohort Profile: The Environmental-Pollution-Induced Neurological EFfects (EPINEF) study, a multicenter cohort study of Korean adults.

General populations are exposed to numerous environmental pollutants, and it is still unclear what pollutants affect the brain, accelerating brain aging and increasing the risk of dementia. The Environmental-Pollution-Induced Neurological Effects study is a multi-city prospective cohort study that aimed to comprehensively investigate the effect of different environmental pollutants on brain structures, neuropsychological function, and development of dementia in adults. The baseline data of 3,775 healthy elderly people were collected from August 2014 to March 2018. The eligibility criteria were ≥ 50 years of age and no self-reported history of dementia, movement disorders, or stroke. The assessment includes demographics and anthropometrics, laboratory test, and individual levels of exposure to air pollution. Additionally, a neuroimaging sub-cohort was recruited with 1,022 participants, during the same period, and brain magnetic resonance imaging and neuropsychological tests were conducted. The first follow-up environmental pollutant measurements will start in 2022 and the follow-up for the sub-cohort is conducted every 3-4 years. We found that subtle structural changes in the brain may be induced by exposure to airborne pollutants such as PM10, PM2.5, and NO2 in healthy adults. This study provides a research base for large-scale, long-term neuroimaging assessment in community-based populations.