Fine particulate air pollution, public service, and under-five mortality: a cross-country empirical study

The impacts of fine particulate matter (PM2.5) air pollution on health outcomes, especially those of children, have attracted worldwide attention. Based on the PM2.5 concentration data of 94 countries including the least developed countries estimated by satellite observations in nearly 20 years, this paper investigates the impacts of PM2.5 pollution on under-five mortality rate (U5MR) and analyzes the role of public service in moderating the PM2.5-mortality relationship. Results indicate that PM2.5 pollution has significantly positive influence on U5MR globally. However, the effects of fine particulate pollution on child mortality are heterogeneous in terms of their significance and degrees in countries with different levels of development. A further test based on panel threshold model reveals that public service, measured by public education spending and sanitation service, plays a positive moderating role in the PM2.5-mortality relationship. Specifically, when the ratio of public education expenditure in GDP of a country exceeds the first threshold value 3.39% and the second threshold value 5.47%, the magnitude of the impacts of PM2.5 pollution on U5MR significantly decreases accordingly. When the percentage of population with access to improved sanitation facilities in a country is over 41.3%, the health damaging effects are reduced by more than half. This paper fills the current gap of PM2.5 research in least developed countries and provides key policy recommendations.