City markers indicating 2025 PM2.5 levels, size adjusted for population μg/m3 in 2025 representing a 5% reduction. At the city level, Bejing, Shanghai, Chongqing, and concentrations compared with 2024, five cities remained the same, and 210 cities recorded Cities in the western province of Xinjang reported a 20% average increase in annual PM2.5 chemical plants,movingwest to capitalize on the region's significant coal reseves.Xinjang is home to the most polluted city in China, Hotan, ranked 2nd most polluted globally, and the city of Aksu who reporting a massive 60% increase in PM2.5 levels compared to 2024. Henan several provinces with historically high concentrations, including Hebei, Henan, Hubei, and and desertification continued to impact air quality.11 In 2025, China's air pollution landscape experienced a distinct geographic shift.While industrial hubs like Bejing, Tianjin, Hebei, and Henan saw modest declines in PM2.5 levels, emissions i u ids uis e po nid un sod sam u ds as pollution. This was driven by the expansion of coal production and the relocation of energy- a'sd e-o-oo pe s snal-uu s unu ssni si industrial migration, combined with sandstorms, biomass burning, and weak enforcement Annual hours spent at different PM2.5 pollution levels targeted improvement initiatives in eastern China are producing results, the overall progress remains uneven as western regions face worsening outcomes, and eastern cities still struggle