The average density of PM2.5 particles in China's three main economic regions dropped dramatically in the first half of 2015, reflecting the government's campaign against air pollution, analysts said.

They said that aside from weather conditions, the influence of the economic downturn and the government's energy-saving and emissions reduction policy also contributed to the drop in the pollutant level.

Data released by the Ministry of Environmental Protection(MEP) on Monday showed that the average density of PM2.5 particles, or particulate matter under 2.5 micrometers in size, in the Beijing-Tianjin-Hebei region, Yangtze River Delta and Pearl River Delta dropped 22 percent, 16.2 percent, and 20.5 percent, respectively, compared to the same period last year.

The PM2.5 level in Beijing alone dropped 15.2 percent in the first half year of 2015.

"The data shows that the government's efforts to curb pollution have had preliminary success and the air quality has improved," Li Zuojun, a deputy director of the Development Research Center of the State Council, told the Global Times.

"Industrial production has slowed down due to the economic downturn and many factories were shut down, lowering the pressure on the environment," Li said.

The average density of PM10 particles, sulfur dioxide and nitrogen dioxide in the Beijing-Tianjin-Hebei region dropped 17.8 percent, 27 percent, and 11.8 percent, respectively.

This is one result of the improvement in China's industrial structure, said Li.

According to data from the National Bureau of Statistics (NBS), the services sector grew by 8.4 percent, accounting for 49.5 percent of GDP in the first half of 2015, while secondary industries rose 6.1 percent.

"Compared with secondary industries, the services industry causes less pollution to the environment," said Li.

Government efforts to implement environment laws and force factories to upgrade or shut down also helped improve the environment, analysts said.

"Weather conditions in the first half of the year helped disperse the pollutants. At the same time, local governments in the three regions took measures to curb pollution, such as restricting vehicles that failed emissions standards and controlling the amount of dust from construction sites," Wei Fusheng, a member of the Chinese Academy of Engineering who specializes in air pollution control, told the Global Times.

Tianjin has retired 290,000 heavy emissions-causing vehicles as of July. Beijing authorities also vowed on Sunday to shut down 1,200 factories by the end of next year.

"A series of laws and educational programs on environmental protection also helped curb air pollution," Wang Canfa, a professor at the China University of Political Science and Law, told the Global Times.

The Environmental Protection Law, which was implemented in January, imposes harsher punishment for environmental violations and has specific articles and provisions on tackling smog.