Mortality and morbidity consequences of particulate matter in South Korea: evidence from transboundary air pollution

Exposure to fine particulate matter (PM_2.5) is harmful to people, leading to respiratory disease and even death. The association between PM_2.5 pollution and health outcomes has become a key foundation for public health policy development. This study aims to quantify the effects of PM_2.5 on health outcomes (mortality, morbidity) and estimate the benefits of reducing PM_2.5 levels in South Korea.

This study uses an instrumental variable (IV) analysis to estimate the effects of PM_2.5 on health outcomes in South Korea, using mortality data for 2015-2022 and morbidity data for 2016-2019. Local air pollution in South Korea is instrumented using a wind-direction indicator with air pollution levels measured at upwind Chinese monitors to address potential endogeneity concerns. Estimates of PM_2.5-related death and the life-year loss are used to calculate the economic benefits of preventing PM_2.5-related deaths.

The results indicate that a 1 µg/m³ increase in local PM_2.5 levels is associated with a 0.17% rise in older (65+) adult mortality rate and a 5.1% increase in respiratory hospitalizations. Significant rises in mortality and morbidity were observed for disease categories directly associated with PM_2.5 pollution. Considering only the avoided life years lost, the 5.58 µg/m³ reduction in PM_2.5 levels achieved in South Korea from 2015 to 2022 corresponds to an estimated economic benefit of USD 14.14 billion. The study also found that a 1 µg/m³ increase in PM_2.5 raised hospital visits by 1.2% for acute upper respiratory infections and 2.6% for lower respiratory infections.

These findings highlight the magnitude and cost of the health risks posed by air pollution, underscoring the importance of effective policies to manage air quality. This study provides clear evidence of the harmful effects of air pollution on human health, particularly on vulnerable groups and related diseases.