Evaluating the Effects of Long-Term Exposure to Fine Particulate Matter (PM_2.5) on Depressive Mood among Korean Older Adults Using Multilevel Analysis

Background: The harmful effects of particulate matter (PM) are amplified in older adults, who experience a decline in physiological function, reducing their ability to expel and detoxify inhaled PM. Moreover, older adults may be more vulnerable to fine particulate toxicity due to underlying medical conditions. We assessed the effects of long-term exposure to fine particulate matter (PM_2.5) on depressive mood (DM) in adults aged > 65 yr using community-based data.

Methods: In the 2017, Korean Community Health Survey (KCHS) data, data of PM_2.5 and community factors were constructed based on participants who responded to DM in a sample of 67,802 individuals. To evaluate the effect of PM_2.5 on DM among older adults, a multilevel regression model was constructed using individual-(KCHS) and community-level data (PM_2.5, green area per capita, urban area, social welfare budget, health, and social business). For PM_2.5, an independent variable, quartiles were used to classify regions according to concentration.

Results: A positive correlation was found between PM_2.5 and DM of older adults. Compared to Q1, the odds ratio increased to 1.15 (95% CI 0.76-1.74) in Q2, 1.55 (95% CI 1.02-2.35) in Q3, and 1.60 (95% CI 1.16-2.20) in Q4.

Conclusion: DM may increase in older individuals living in areas with high PM_2.5. Systematic mental health management is required for older individuals residing in such areas.