BEIJING, March 17 -- The number of Chinese cities that suffered "heavy" or "grave" air pollution during the Lunar New Year celebrations in mid-February dropped sharply from previous years.

Thanks to measures to curb the use of fireworks and firecrackers, fewer cities witnessed serious air pollution on Lunar New Year's eve which fell on February 18 this year, according to a statement released Tuesday by the Ministry of Environmental Protection.

Official figures show that 74 major cities saw 59.9 percent of days with decent air quality in February, down 0.4 percentage points year-on-year.

The 25 cities monitored in the Yangtze River Delta saw 65.3 percent of days with sound air quality while nine cities in the Pearl River Delta region had 75.3 percent days with clear air in February, the statement said.

The notoriously-polluted Beijing-Tianjin-Hebei region reported39.9 percent of days with air quality that met the national standard for clear air.

The thirteen cities in the region saw 19.2 percent of days with air quality in the "heavy" and "grave" range.

The top ten polluted cities included six in north China's Hebei Province, along with Shenyang, Harbin, Urumqi and Zhengzhou.

In general, the major air pollutant in the country was PM2.5, followed by PM10, the statement said.

China began to include an index of PM2.5, a key indicator of air pollution, and ozone in a new air quality standard at the beginning of 2013. The 74 cities have been chosen as pilots for the new standard.