Efforts to clean air bear fruit

Most Chinese regions with pollution problems made significant progress last year in their efforts to improve air quality because of regulators' measures to curb smog, a report released on Friday said.

The average PM2.5 concentration in 10 polluted Chinese regions declined by 11.9 percent year-on-year in 2014, said the report from the Clean Air Alliance of China, a Beijing think tank.

PM2.5 refers to tiny particles in the air 2.5 micrometers in diameter or smaller. Such particles can penetrate deep into the lungs.