Impact of population and primary energy consumption on air pollutants of 67 countries

Air pollution is one of the most pressing environmental issues in the world today. To predict the air quality of 67 countries, considering the influence factors including population and primary energy consumption, an unequal-order exponential cumulative grey multivariate model is proposed to predict the PM2.5 concentrations. The prediction results show that South and Southeast Asia are the most polluted regions in Asia. Eastern and Central Europe are the most polluted regions in Europe. North and West Africa are the most polluted regions in Africa. In terms of air quality, Oceania is the best continent. Air quality in North America is likely to deteriorate in the coming years. The situation in South America is also not optimistic. The results of this study can provide the government with a basis to adjust the local environmental policy in order to improve air quality. The public can deal with air pollution and take appropriate precautions.