Poor air quality hits many big cities

Haihe River in North China rated most polluted river in the country

BEIJING - The average air quality in 45 major cities - nearly four out of every 10 major cities in the country - was rated as "poor" in the first half of this year, according to the Ministry of Environmental Protection.

Urumqi, capital of Northwest China's Xinjiang Uygur autonomous region, recorded the highest level of pollution.