在近日举行的2010年中国汽车产业发展论坛上,环保部科技标准司副司长刘志全指出,目前全国约五分之一的城市大气污染严重,113个重点城市中三分之一以上空气质量达不到国家二级标准,机动车排放成为部分大中城市大气污染的主要来源。 At the 2010 China Automotive Industry Development Forum held recently, Liu Zhiguan, deputy director of the Science and Technology Standards Department of the Ministry of Environmental Protection, pointed out that at present about one-fifth of the cities in the country are seriously polluted by air and over one-third of the 113 key cities have air quality up to Less than two national standards, motor vehicle emissions as part of the major sources of air pollution in large and medium-sized cities.