Beijing, February 23 (People's Daily Online) -- The Ministry of Environmental Protection recently released January 2017 national and Beijing-Tianjin-Hebei, Yangtze River Delta, Pearl River Delta regions and municipalities directly under the central government, provincial capitals, cities separately planned air quality. The percentage of good days in 338 cities at or above the prefecture level was 60.0 percent, down 6.7 percentage points year on year. PM2.5 and PM10 concentrations were 78 micrograms per cubic meter and 117 micrograms per cubic meter, respectively, both up 14.7 percent year on year.

Liu Zhiquan, head of the ministry's environmental monitoring department, said the 10 cities with poor air quality among 74 in January were Shijiazhuang, Xingtai, Handan, Baoding, Urumqi, Xi 'an, Taiyuan, Hengshui, Zhengzhou and Tangshan. The top 10 cities with relatively good air quality (from 1st to 10th) are: Haikou, Zhoushan, Lhasa, Kunming, Lishui, Fuzhou, Taizhou, Xiamen, Shenzhen and Huizhou.

The proportion of good days in 13 cities in the Beijing-Tianjin-Hebei region was 36.2 percent, down 19.6 percentage points year on year. The PM2.5 concentration was 128 micrograms per cubic meter, up 43.8 percent year on year. The concentration of PM10 was 189 micrograms per cubic meter, up 41.0% year-on-year.

The proportion of good days in Beijing was 51.6 percent, down 19.4 percentage points year on year. The PM2.5 concentration was 116 micrograms per cubic meter, up 70.6% year on year; The concentration of PM10 was 131 micrograms per cubic meter, up 63.8% year-on-year.

The proportion of good days in 25 cities in the Yangtze River Delta was 74.1 percent, up 16.2 percentage points year on year. PM2.5 concentration was 60 micrograms per cubic meter, down 16.7 percent year on year; The concentration of PM10 was 86 micrograms per cubic meter, down 18.9% year on year.

The proportion of good days in nine cities in the Pearl River Delta region was 84.2%, down 13.3 percentage points year-on-year. PM2.5 concentration was 51 micrograms per cubic meter, up 59.4% year on year; The concentration of PM10 was 69 micrograms per cubic meter, which reached the national second-class average annual concentration standard.