Ambient PM2.5 exposure and rapid population aging: A double threat to public health in the Republic of Korea
Na Rae Kim, Hyung Joo Lee
Abstract
Particulate matter with an aerodynamic diameter of ≤2.5 μm (PM 2.5 ) can infiltrate deep into the respiratory system, posing significant health risks. Notably, the health burden of PM 2.5 is more pronounced among the older adult population. With an aging population, the public health burden attributable to PM 2.5 could escalate even if the current PM 2.5 level remains stable. This study evaluated the number of deaths attributable to long-term PM 2.5 exposure in the Republic of Korea between 2020 and 2050 and identified the PM 2.5 concentration required at least to maintain the current PM 2.5 health burden. To calculate mortality for 2020–2050, we performed a health impact assessment using 3-year (2019–2021) average population-weighted PM 2.5 concentrations, age-specific population and mortality rates. In 2020, 33,578 [95% confidence interval (CI) = 31,708–35,448] deaths were attributable to PM 2.5 exposure. Projecting forward, if the 2019–2021 average PM 2.5 level remains constant, mortality is projected to be 112,953 (95% CI = 109,963–115,943) in 2050, more than three times higher than in 2020. To maintain the same level of health burden in 2050 as in 2020, the PM 2.5 concentration needs to be immediately reduced to 5.8 μg/m 3 . In an age-specific analysis, the proportion of older adults (ages 65+) to total mortality would increase from 83% (2020) to 96% (2050), indicating that the rising mortality is predominantly driven by the aging population. By region, the reduction of PM 2.5 concentrations, which is required immediately in 2020 to have the health burden in 2050 equal to that in 2020, varied from 3.6 μg/m 3 in Goheung-gun (25% reduction) to 20.8 μg/m 3 in Heungdeok-gu (82% reduction). Our study emphasizes the critical need for air quality management to consider aging populations when establishing PM 2.5 air quality standards, as well as their associated policies and regulations. • PM 2.5 -related mortality was assessed in relation to rapid population aging in Korea. • The proportion of older adults (ages 65+) is projected to increase to 40% by 2050. • Due to rapid aging, PM 2.5 -related mortality is expected to increase by 79,375 by 2050. • To offset the aging impacts, PM 2.5 levels need to decrease to 5.8 μg/m 3 .