BEIJING, Dec. 22 (Xinhuanet) -- This national capital of Beijing had 230 days of "blue sky" as of Wednesday this year, meeting the pre-set target for the year 10 days ahead of schedule.

　　It is the seventh year in a row of improvement in air quality in the national capital, sai d Du Shaozhong, deputy head of the municipal bureau of environmental protection.

　　Greater efforts were made to improve the quality of air in Beijing this year.

　　According to Du, the national capital removed 4,000 old polluting buses and 30,000 cabs from service this year and replaced them with new vehicles meeting newly promulgated, more rigid state standards for pollution control.

　　Additionally, on July 1 it began implementing local standards for environment protection concerning fuel of motor vehicles commensurate with the new standards for exhaust of motor vehicles.

　　In the meantime, the relevant departments of the city tightened monitoring different sources of pollution and law enforcement in this regard, which also contributed a lot to the city's "blue sky"plan. Enditem