Long-term exposure to fine particulate matter concentrations and cause-specific mortality and incidence in an aging society

다국어 초록 (Multilingual Abstract)

Long-term exposure to particulate matter less than 2.5 μm (PM2.5) is considered a risk factor for premature death. However, only a few studies have been conducted in areas with moderate PM2.5 concentrations. Moreover, an aging society may be more susceptible to environmental exposure and future burden of mortality and incidence due to PM2.5. This study estimates hazard ratios (HRs) for all-cause and cause-specific mortality and incidence from long-term exposure to moderate PM2.5 concentrations in the elderly populations of seven cities in South Korea. We also projected nationwide elderly mortality caused by long-term exposure to PM2.5, accounting for population aging until 2045. Mortality and incidence in 1,720,230 elderly adults aged 65 years and older in 2008 was monitored across 2009–2016 and linked to modeled PM2.5 concentrations. A total of 421,100 deaths occurred in 2009–2016, and the mean of annual PM2.5 concentration ranged between 21.1 μg/m3 and 31.9 μg/m3 in most regions. The overall HR for a 10 μg/m3 increase in a 36-month PM2.5 moving average was 1.024 [95% confidence intervals (CI): 1.009, 1.039]. We estimated that 11,833 all-cause nationwide elderly deaths were attributable to PM2.5 exposure. Annual death tolls may increase to 17,948 by 2045. However, if PM2.5 is reduced to 5 μg/m3 by 2045, the tolls may show a lower increase to 3,646. Among cause-specific incidence, 54,522 and 259,700 developed asthma and chronic obstructive pulmonary disease (COPD), respectively. A 10 μg/m3 increase in the 36- and 60-month mean PM2.5 concentration was significantly associated with a 9% increase in incident asthma (HR=1.09, 95% CI: 1.04–1.14) and COPD (HR=1.09, 95% CI: 1.07, 1.11). The long-term exposure to moderately high levels of PM2.5 was associated with increased mortality and incidence risk among the elderly. Thus, PM2.5 reduction in response to the projected aging-associated mortality and incidence in South Korea is critical.