An Evaluation of the Air Quality Warning System for Vulnerable and Susceptible Individuals in South Korea

Background Since 1987, WHO has periodically published international air quality guidelines and standards, and governments around the world have set the Air Quality Index (AQI) to monitor air pollution according to the characteristics of individual countries. The set AQI is used for the operation of a forecast and alarm system for air quality. There are many studies on these forecast and warning systems, but evidence of their effectiveness is still limited. Objectives The purpose is to understand the effectiveness of the air quality alert system implemented in January 2015 through the change in the incidence rate of environmental diseases. Method The study adopted interrupted time series analysis with Poisson segmented regression to detect changes in the incidence rate of environmental diseases after implementing the Air Quality Warning System (AQWS) in Korea using data from 2010 to 2019. Seasonality, air pollutants (CO, NO2, SO2, PM10, and O3), temperature, and humidity are used for adjustment variables. The findings were validated using false policy study periods and digestive diseases as a control. Result After implementation of the AQWS, the incidence of COPD gradually decreased by 24% (relative risk (RR) 0.76, 95% confidence interval (CI) 0.65-0.88). Asthma and Heart Failure similarly tended to decrease (Asthma : RR 0.37 95%CI 0.21-0.65, HF : RR 0.37 95%CI 0.21-0.65), which was statistically significant. There was a gradual effect on the incidence rate of asthma in both children and the elderly, decreasing 44% and 22%, respectively. In the elderly, the same tendency was found in COPD (RR 0.81, 95%CI 0.70-0.94) and HF (RR 0.95, 95%CI 0.90-0.99). Conclusion In Korea, the AQWS was effective in most environmental diseases. It is expected that the health benefits of the policy can be maximized if AQWS warns the degree of risk reflecting the characteristics of vulnerable and sensitive individuals.