Effect of Severe External Airborne Agents' Exposure on Dementia.

The impact of occupational and environmental exposure to external airborne agents on cognitive function, especially in incidence of dementia, is understudied. The present study was conducted to elucidate the association between severe external airborne agents' exposure and incidence of dementia among an elderly population and to explore the effects of exposure to severe external airborne agents on preclinical dementia using the screening test of dementia. From the National Health Insurance Service-Health Screening Cohort (NHIS-HealS, 2002-2015), 514,580 participants were used for data analysis. We estimated the standardized incidence ratio (SIR) according to the exposure to external airborne agents. Of the total participants (n = 514,580), 1340 (0.3%) experienced severe external airborne agents exposure, and 26,050 (5.1%) had been diagnosed with dementia. The SIRs (95%CI) of dementia in Alzheimer's disease, vascular dementia, dementia in other diseases, and unspecific dementia were 1.24 (1.01-1.49), 0.88 (0.37-1.32), 1.16 (0.01-2.77), and 0.69 (0.36-1.02), respectively. The risk of testing positive in the dementia screening significantly increased with exposure to severe external airborne agents after adjusting for all confounding variables. This study found that exposure to severe external airborne agents is a potential risk factor for dementia, especially in Alzheimer's disease. It is essential to create international awareness regarding the effect of airborne agents' exposure on dementia.