IV. Divergent Trends of Fine and Coarse Particulate Matter: PM10 Improvement Driven Largely by PM2.5 Declines
From 2015 to 2025, the average PM10 concentration across 18 provinces and municipalities dropped by 41.6 micrograms per cubic metre, with PM2.5 accounting for 64.9% of this total reduction. In other words, nearly two-thirds of the overall improvement in PM10 stemmed from falling fine particulate matter levels.
During the 14th Five-Year Plan period, the average urban reduction rate of coarse particulate matter (PM10-2.5) stood at 9.3%, lower than the 11.7% recorded for PM2.5. The divergence widened notably in 2025: PM2.5 concentrations fell by 1.3 micrograms per cubic metre year-on-year, while coarse particulate matter concentrations rose by 1.1 micrograms per cubic metre over the same period.
Time series of meteorology-adjusted annual average PM2.5 and PM10 concentrations (μg/m³) from 2016 to 2025 across the "4 municipalities plus 173 cities"
Regional breakdown reveals that coarse particulate matter concentration on the Fenwei Plain reached 41.3 μg/m³, exceeding the PM2.5 level of 36.5 μg/m³, in stark contrast to the Beijing-Tianjin-Hebei surrounding region (32.9 μg/m³) and the Yangtze River Delta (22.7 μg/m³). A clear upward rebound trend in particulate pollution is observed in Northwest China, with rising PM10 concentrations recorded in Gansu, Ningxia and Qinghai.
The report notes that the PM2.5-centered governance strategy has delivered remarkable results in controlling fine particulate matter and its precursors. Nevertheless, more targeted measures are required to curb fugitive dust and other coarse particulate sources. It proposes a shift in particulate pollution governance from a "fine particulate matter-dominated" model to coordinated control of both fine and coarse particles. To address the lagging improvement of PM10 in Northwest China and the Fenwei Plain, refined management of fugitive dust from construction sites, road surfaces, material stockyards and bare land should be strengthened.
