Air pollution in China, particularly PM2.5 pollution, has worsened due to rapid economic growth. A study analyzed data from 2001-2018 to measure PM2.5 environmental efficiency, finding an average score of 0.702, indicating inefficiency. Scores varied across regions and provinces. Economic development has a U-shaped relationship with PM2.5 environmental efficiency, unlike the traditional environmental Kuznets curve. Technological innovation, trade dependency, and regional development positively impact PM2.5 environmental efficiency, while environmental regulations, industrial structure, and population density have negative effects. Foreign direct investment does not lead to a "pollution haven" in China.