Most of China’s 74 major cities failed to reach the national standards in six key air quality metrics in 2014, the national environmental watchdog said on Feb 2.

Of the 10 cities with the worst pollution, eight were in the Beijing-Tianjin-Hebei area. Baoding, in Hebei province－the southern neighbor of the capital－topped the list, highlighting the lingering challenges faced by governments in the trilateral zone.

The Ministry of Environmental Protection released its annual report on the air quality of the 74 major cities on Feb 2, saying 66 of them failed to meet standards for six major airborne pollutants, including the concentration of PM2.5 and nitrogen oxides.

Cities in Hebei, a province reliant on heavy industries such as iron and steel, continued to dominate the top 10－Baoding, Xingtai, Shijiazhuang, Tangshan, Handan, Hengshui and Langfang.

The average concentration of PM2.5 in the trilateral zone was 93 micrograms per cubic meter last year, 160 percent above the national average, the report said.

Compared with two other major industrial zones, the Yangtze River Delta and Pearl River Delta, the Beijing-Tianjin-Hebei area had far worse air pollution, with PM2.5 concentrations double that of the southern industrial zones. The Pearl River Delta measured 42 micrograms per cubic meter, for example.

Chang Jiwen, deputy director of the Research Institute of Resources and Environment Policies at the Development Research Center of the State Council said some funds for air pollution control projects in the region were not used well, reducing the effectiveness of some efforts.

Yet the trilateral region has made some achievements, said Gong Zhengyu of the China National Environmental Monitoring Center under the ministry. “We have witnessed more days of clean air in more cities, and greater reductions in the concentration of PM 2.5, the major airborne pollutant,” he said.

In 2013, only three cities－Haikou, in Hainan province; Lhasa, in the Tibet autonomous region; and Zhoushan, in Zhejiang province－met national standards for air quality.

In 2014, the number increased to eight, with more coastal cities joining in.

“Also, the concentration of PM2.5 in Beijing-Tianjin-Hebei region was reduced from 106 micrograms in 2013 to last year’s 93 micrograms, which is huge progress,” Gong said.