This paper investigates the impact of air quality pollution on respiratory health risk in Korea. In particular, we consider transboundary effects of particulate matter (PM10) on the health risk of pneumonia by using the spatial panel model. PM10, generated by natural phenomena and anthropogenic activities, migrates to neighboring areas contributing to not only local but also ambient regional health risks. We employ the spatial panel model to explain the spillover effects of air pollution on the respiratory health risk. The panel data covers environmental, demographic and economic variables that are associated with pneumonia of 120 local districts in Korea during the period from 2010 to 2015. Empirical evidence based on non-spatial and spatial models commonly indicates that the impact of air pollution on pneumonia-related risk is significant. The spatial panel model assessment reveals improvement in explanation and evidences more significant effect of ambient air pollution on pneumonia related hospital visits. As such, evidences of spatial dependence and borderless impacts of air pollution on the health risk of pneumonia are found to be strong. We also investigate the spatial dynamics of the potential association between air pollution and respiratory diseases with respect to variations in wind direction by extending the conventional weight matrix specification. Empirical results imply that transboundary effects of PM10 on health risk are stronger for districts located downwind from Northwest districts than from other directions.