Evaluation of an air quality warning system for vulnerable and susceptible individuals in Korea: an interrupted time series analysis

OBJECTIVES: This study was conducted to elucidate the effects of an air quality warning system (AQWS) implemented in January 2015 in Korea by analyzing changes in the incidence and exacerbation rates of environmental diseases.METHODS: Data from patients with environmental diseases were extracted from the National Health Insurance Service -Na-tional Sample Cohort database from 2010 to 2019, and data on environmental risk factors were acquired from the AirKorea da-tabase. Patient and meteorological data were linked based on residential area. An interrupted time series analysis with Poisson segmented regression was used to compare the rates before and after AQWS introduction. Adjustment variables included sea-sonality, air pollutants (carbon monoxide, nitrogen dioxide, sulfur dioxide, particulate matter less than 10 i.tm in diameter, and ozone), temperature, and humidity.RESULTS: After AQWS implementation, the incidence of asthma gradually decreased by 20.5%. Cardiovascular disease and stroke incidence also significantly decreased (by 34.3 and 43.0%, respectively). However, no immediate or gradual decrease was identified in the exacerbation rate of any environmental disease after AQWS implementation. Sensitivity analyses were performed according to age, disability, and health insurance coverage type. Overall, the AQWS effectively mitigated the occurrence of most environmental diseases in Korea. However, the relationships between alarm system implementation and reduced incidence dif-fered among diseases based on the characteristics of vulnerable and sensitive individuals.CONCLUSIONS: Our results suggest that by tailoring the AQWS to demographic and sociological characteristics and provid-ing enhanced education about the warning system, interventions can become an efficient policy tool to decrease air pollution-related health risks.

Automated summary

This study investigates the effects of an air quality warning system (AQWS) implemented in Korea in 2015 on the incidence and exacerbation rates of environmental diseases. The results show that the AQWS has led to a gradual decrease in asthma incidence, as well as significant decreases in cardiovascular disease and stroke incidence. However, there was no immediate or gradual decrease in the exacerbation rate of any environmental disease. The findings suggest that tailoring the AQWS to demographic and sociological characteristics and providing enhanced education can effectively reduce air pollution-related health risks.