BEIJING -- Only nine of 161 Chinese cities reached the new -- and stricter -- air quality monitoring standards in the first half of this year, according to the Ministry of Environmental Protection (MEP).

Zhoushan, Shenzhen, Zhuhai, Zhanjiang, Yunfu, Beihai, Sanya and Lhasa are the cities which reached the standard, the ministry said.

China in February 2012 issued a new air quality monitoring standard which includes the monitoring of ozone, carbon monoxide and PM2.5, plus that of PM10, sulfur dioxide and nitrogen dioxide.

Of 166 cities that have not yet implemented the new standard, 105 reached standard, 63.3 percent of the total, a 7.1 percentage point drop compared to the same period of last year.

Cities using new standard are mainly located in north China's Hebei Province and the neighboring Beijing, Tianjin, the Yangtze River Delta in the east, the Pearl River Delta in the south.

The ministry ranks and publishes the air quality indices of 74 major cities on a monthly basis. Compared to 2013, air quality in the 74 cities has improved. The days reaching standard on average increased from 58.7 percent to 60.3 percent.