Global spatial and temporal patterns of fine particulate concentrations and exposure risk assessment in the context of SDG indicator 11.6.2

Assessing the spatiotemporal patterns, exposure risks and sustainability of PM2.5 pollution from multi-scale spatial and temporal characteristics are relevant for achieving Goal 11.6.2 of the 2030 Agenda for Sustainable Development (assessing the effects of urban fine particulate matter pollution on public health). According to this study, methodological models combining trend analysis, spatial statistics, and population exposure risk assess the spatiotemporal patterns, exposure risks, and sustainability characteristics of PM2.5 pollution at global, continental, and national scales, and ultimately achieve SDG 11.6.2 Assessment framework at different spatial scales. The results indicate that: (1) The annual decline in global PM2.5 concentrations exhibited a rate of -0.023 mu g/m(3)/yr, with more than 30 % of regions experiencing a decrease in PM2.5 concentrations of more than 0.1 mu g/m(3)/yr, and showed significant spatial distribution differences. (2) The global population exposed to <10 g/m(3) continues to grow from 4.8 % in 2000 to 6.2 % in 2010 and further to 10.3 % in 2020 during the study period. By comparison, the population exposed to >70 mu g/m(3) shows a U-shaped change. Spatially, more than 60 % of the world's regions are exposed to low risk (Low risk and Lower risk) and less than 30 % are exposed to high risk (Higher, High and Extremely high risk). Asia has the highest exposure (2.95), while Oceania has the lowest (0.11). (3) Inequalities in sustainable PM2.5 exposure risks between developed and developing countries will continually increase. The results of the study not only shed light on the present state of sustainable global air quality progress but also offer valuable insights and a blueprint for conducting similar multi-scale assessments in the coming times.