Some literature has documented ambient fine particulate matter (PM2.5) pollution and corresponding health burden in China, however, the knowledge of spatial disequilibrium of PM2.5 and PM2.5-induced disease burden is scarce. With the help of gravity center model, spatial autocorrelation analysis as well as the region-specific exposure-response coefficient and ground-based PM2.5 daily concentrations over 336 cities in China from January 2016 to December 2017, this paper provides a completive assessment for spatial disequilibrium of PM2.5-induced health burden. Improving PM2.5 concentrations and declining PM2.5-induced health burden were found in China. The 2-year city-average concentration of the 336 cities was 45 +/- 17 mu g/m(3) with a range from 11 mu g/m(3) to 128 mu g/m(3). PM2.5-related deaths from stroke, ischemic heart disease, chronic obstructive pulmonary disease, hypertensive heart disease and lower respiratory infection amounted to 0.766 million in 2016 and 0.720 million in 2017. Much higher but decreasing PM2.5-induced mortality happened in the west, while higher and increasing PM2.5-induced deaths existed in the south. Strong spatial autocorrelation of PM2.5 and PM2.5-induced disease burden existed among cities, illustrated by high-high (HH) clusters with significant spatial homogeneity and spatial spillover effect. The cities included in PM(2.5 )concentration HH cluster had average PM2.5 concentration 68.5 mu g/m(3), about 1.5 times higher than the national average; the cities involved in combined mortality HH cluster had mortality 90.5/10(5), 1.8 times as much as the national city-average level; about 46.4% of PM2.5-induced combined deaths happened in HH cluster cities. The cities embraced in the HH clusters of PM2.5 concentration, population, deaths and mortality simultaneously, mostly located in Hebei, Shandong and Henan provinces, should be the top priorities for joint air pollution control. This paper provides important implications for policymakers regarding priority areas of joint air pollution control in China. (C) 2019 Elsevier Ltd. All rights reserved.

Massive monitoring data requires effective statistical analysis methods. This paper aims to visualize the spatiotemporal characteristics and spillover effect of air pollutants. Ground-based PM2.5 data in 336 cities across China revealed a tough but improving situation. The PM2.5 average annual concentrations in 2016 and 2017 were 47 ± 18 µg/m3 and 44 ± 16 µg/m3 respectively, but a worse, or at least a not-improving PM2.5 situation happened in winter. A slight declining north-south disequilibrium and a growing east-west disequilibrium exhibited in 2017, along with an increasing weight of eastern and southern pollution in the proportion of the overall pollution level. North-south disequilibrium existed stably throughout the year but east-west disequilibrium was erratic. Nearly half of the cities exhibited significant spillover effects, presenting 2 clusters with spillover by high concentrations and 3 clusters with spillover by low concentrations. Most cities in Hebei, Shandong and Henan provinces showed a high but decreasing spillover effect, but increasing trend happened in the cities in Anhui and Shanxi provinces. A significant correlation appeared between the city population and PM2.5 concentration. Population density explained about 25% of the PM2.5 concentration change, and the explanation ability increased in 2017. A higher influence of population on PM2.5 concentration happened in the early stage of city development, and the influence exhibited spatial differences. The city population and PM2.5 spillover effect existed an overall positive correlation, but the population only addressed about 10% of the spillover effect change. Our findings provide important information for the joint prevention and control of air pollution in China, and the approach proposed in this paper is applicable to other fields.