MEP official recently released air quality of key regions and 74 cities in October of 2013 including Beijing-Tianjin-Hebei Province, the Yangtze River Delta, the Pearl River Delta, municipalities, provincial capitals and cities separately listed on the state plan.　

According to the monitoring results, the ratio of days with up-to-standard air quality among the 74 cities ranged between 3.2% and 100% with an average of 52.2%. Days with substandard air quality accounted for 47.8% on average, among which days of slight pollution made up 29.8%, intermediate pollution 9.7%, heavy pollution 6.3% and severe pollution 2.0%. In Fuzhou and Wenzhou, all days were up to standard. In 13 cities including Shanghai, Xining and Nantong, about 80% of the days were up to standard. The percentage of up-to-standard air quality in 24 cities including Changzhou, Chengde and Dalian was between 50% and 80% and that in half cities was less than 50%. Specifically, Harbin suffered from severe air pollution from Oct. 19 to 23. Polluted days were mostly caused by PM2.5 and O3, taking up 61.7% and 25.1% respectively. Compared with September, the concentration of major pollutants has all increased except O3 due to the change of the season from autumn to winter. The level of PM2.5 and PM10 rose by 46.2% and 39.6% respectively. According to the assessment of air quality by comprehensive pollution index, the top ten cities with poor air quality in October were as follows: Shijiazhuang, Xingtai, Baoding, Handan, Tangshan, Jinan, Harbin, Hengshui, Xi’an and Wuhan. The top ten cities enjoying good air quality included Zhoushan, Fuzhou, Shanghai, Taizhou, Nantong, Haikou, Xiamen, Lhasa, Zhangjiakou and Yancheng. Compared with the previous month, air quality in Zhoushan, Fuzhou, Shanghai, Taizhou, Haikou, Xiamen and Lhasa stayed good while that of Nantong, Zhangjiakou and Yancheng has improved dramatically, among which Zhangjiakou had 83.9% of days with up-to-standard air quality.

In Beijing-Tianjin-Hebei Province, the days with up-to-standard air quality in 13 cities accounted for 3.2% -83.9%, averaging 37.2%. Days of substandard air quality accounted for 62.8% on average including 16.4% of the days suffering from heavy pollution and 8.4% severe pollution. Among the 13 cities, days with up-to-standard air quality in Zhangjiakou accounted for 83.9% and the percentage for Chengde, Qinhuangdao and Beijing was between 50% and 80%. Other cities had less than 50% of days meeting air quality standard. PM2.5 and O3 were the major culprits of air pollution, resulting in 68.8% and 30.4% of pollution days respectively. Compared with September, the average ratio of up-to-standard days in the 13 cities dropped by 3.7 percentage points.

Among the 25 cities in the Yangtze River Delta, the proportion of up-to-standard days stood at between 35.5% and 100% with an average of 73.5%. The average days with substandard air quality accounted for 26.5% which included 0.9% heavy pollution days. No severe air pollution occurred in the region. Among the 25 cities, Wenzhou enjoyed good air quality throughout the month. About 80%-100% of days in Shanghai, Nantong, Zhoushan and other five cities were of up-to-standard air quality. 14 cities including Changzhou, Lishui and Yancheng had 50%-80% of days with up-to-standard air quality, while Xuzhou and Jinhua had less than 50% of days with up-to-standard air quality. Air pollution in the Yangtze River Delta was mostly caused by PM2.5, accounting for 75.1% of the total. O3, the second major pollutant, led to 20.0% of the total pollution days. Compared with September, the average days with up-to-standard air quality in the 25 cities in the Yangtze River Delta went down by 4.9 percentage points.

In the nine cities of the Pearl River Delta, around 3.2% -41.9% days met air quality standard, bringing the average ratio of up-to-standard days to 22.2%. Polluted days accounted for 77.8% on average including 0.4% of heavy pollution days. No severe pollution took place. Days with up-to-standard air quality in all the nine cities were all less than 50%. The Pearl River Delta was mainly polluted by O3, which caused 83.9% of the total pollution days. PM2.5 was the second biggest pollutant, leading to 16.1% of the pollution days. Compared with September, air quality in the region worsened considerably due to reduction in rainfall and increase in solar radiation. The concentration of PM2.5 and PM10 rose by 89.5% and 73.8% respectively. The eight-hour maximum value of O3 during the day exceeded the standard by 39.4 percentage points on average and the average days of up-to-standard concentration slumped by 43.8 percentage points.