Many of China's cities continue to face serious pollution problems that fail to meet national standards, a Thursday report by central environmental authorities revealed.

According to the 2015 Environment Condition Communiqué recently released by the Ministry of Environmental Protection (MEP), only 73 of 338 Chinese cities subject to air quality monitoring met the national standard for clean air in 2015.

Additionally, environmental authorities detected acid rain in 22.5 percent of the 480 cities where they observed precipitation last year, the communiqué stated.

Authorities also conducted tests of drinking water sources for 338 cities and found that the water in nearly 3 percent of them was unfit for human consumption.

However, there were also some improvements in 2015. For example, the number of deaths due to flooding dropped 76 percent from the previous year, while the number of residents affected by floods declined by 46 percent and the area affected by floods declined by 45 percent.

Forest coverage throughout the country has reached 21.6 percent to rank fifth in the world in total forested area, the communiqué reported.

Beijing rolled out a variety of policies to address air pollution and congestion in 2015, including regulations banning vehicles from using the capital's roads on one out of five weekdays based on the last digit of their license plate.

But air quality around Beijing only improved marginally last year, as MEP statistics show that the capital recorded 186 days of air quality that met standards in 2015, just 14 more days than the year before.