Analyzing the socioeconomic determinants of PM2.5 air pollution at the global level

Since PM2.5 pollution has jeopardized public health, the research on how ambient fine particulate matter (PM2.5) concentrations are influenced has been increasingly important for the implementation of regional PM2.5 concentration reduction. This study analyzed the socioeconomic determinants of PM2.5 air pollution of 132 countries/economies. It was found that the main inhibitor for the PM2.5 air pollution is the emission intensity (EmI), which is measured by the PM2.5 emission when a united of energy is consumed, in every income level of countries, while the energy intensity (EnI) is the second inhibitor. Meanwhile, economic output (EO) was the largest driving factor on the PM2.5 concentrations, while population (P) growth was the second. Overall, the national employment rate (Emp) showed very little impact on the countries. This study also analyzed the income-based variation in the effects of the five factors on PM2.5 concentration changes: overall, the effects of the determinants all decreased with the rise of income levels, i.e., both the inhibiting effects of PM2.5 EmI and EnI and driving effects of EO and P performed stronger in lower-income countries than higher-income ones. Regarding the income-based variation of the determinants, this study also discussed the policy implications, such as adopting technologies on reducing PM2.5 intensity and EnI, transferring the EO from the manufacturing industry to the service industry, and international organizations on public health and environmental protection should provide targeted strategies, guidelines, and other assistances to lower-income countries as both driving and inhibiting factors performed more influential on their PM2.5 concentration changes.