According to the Ministry of Environmental Protection, from October 1 to 24, there were 94 days of severe pollution and 27 days of serious pollution reported in 74 cities. Among those, the largest pollution spanned over 560,000 square kilometers (216,217 square miles). Regions in Beijing, Tianjin, Shandong Province and the Northeastern region were the most heavily polluted areas. For the same period in 2013, severe pollution days were 96 and serious pollution days were 33. However, in Beijing, Tianjin, Shandong Province and the nearby region, even though the number of severe pollution days went down from 24 to 21 days, the serious pollution days went up from 49 days in 2013 to 70 days in 2014.
Source: Xinhua, October 26, 2014
http://news.xinhuanet.com/fortune/2014-10/26/c_127141232.htm