Public Health.

Background: The global increase in the aging population has led to a corresponding rise in dementia cases. This study explores the potential link between occupational toxin exposure and the incidence of dementia, aiming to identify high-risk populations.

Method: We analyzed data from 2,485 male participants aged 60 and over in the Korean Longitudinal Study on Cognitive Ageing and Dementia (KLOSCAD). Participants were categorized into no or very low, low and high toxin exposure risk groups based on their lifetime occupation according to the International Standard Classification of Occupations classification. Exposure to the specific hazard type, including carcinogens, skin sensitizers, airway sensitizers, mutagenic substances, reprotoxic agents and biological hazards were identified in relation to their lifetime occupation. We conducted multinomial logistic regression analysis, adjusting for occupation-related factors, APOE genotype, age, education, health status and lifestyle behaviors, to investigate the relationship between the levels of toxin exposure risk, specific toxin types, and the incidence of mild cognitive impairment (MCI), Alzheimer's disease (AD) dementia and other dementia.

Result: Compared to the no or very low toxin exposure risk group, participants in the low toxin risk exposure group (odds ratio (OR) 2.24, 95% CI 1.08 - 43.64) and high toxin risk exposure group (OR 2.97, 95% CI 1.31 - 6.74) showed a significantly increased risk of AD dementia. Exposure to carcinogens, skin sensitisers, reprotoxic agents and biological hazards showed a significant association with the risk of incident AD dementia. Among toxin types, skin sensitizers presented the highest OR of 5.48 (95% CI 1.29-23.31) in multivariable model. No significant associations were found with MCI and other dementia.

Conclusion: Higher risk of lifetime occupational toxin exposure may be associated with an increased risk of AD dementia, showing consistent results across various toxin types, underscoring the need for heightened attention to toxin exposure in AD dementia prevention.