Abstract:
Air pollution warnings aim to protect public health by encouraging people to stay indoors during high-pollution episodes. However, such behavioral responses may unintentionally increase the risk of communicable disease transmission through indoor crowding. Using daily province-level panel data from South Korea (2015–2019), I find that particulate matter warnings significantly raise influenza incidence, especially among children and teenagers. The effect emerges gradually, peaking 25–40 days after a warning. The impacts are stronger after the 2017 introduction of mobile Emergency Disaster Texts, as well as on business days and in dense, lower-income areas. An event study with non-overlapping exposure windows shows no pre-trend, supporting a causal interpretation. These results highlight a behavioral spillover of environmental policy and underscore a public health trade-off: while alerts reduce pollution exposure, they may amplify viral transmission risk.


Keywords: Air pollution; Behavioral response; Information policy; Influenza; Alert