Expert says industrial discharges contributed most to pollution

Air quality in China's cities in April was not as good as the same period last year, the Ministry of Ecology and Environment said on Thursday.

The 338 cities monitored saw only about 20 days of good air during the month, a year-on-year decrease of 5.3 percent.

However, the average density of PM2.5 harmful to health in these cities was about the same as the previous April, at 58 micrograms per cubic meter, the ministry said.

Tangshan, Xingtai, Shijiazhuang, Handan, Langfang and Baoding, Hebei province; Taiyuan, Shanxi province; Changzhou and Yangzhou, Jiangsu province; and Beijing were listed as the 10 cities with the worst air quality in April.

The ministry said that nearly 80 percent of the days from January to April had good air, up 0.9 percent year-on-year. The average PM2.5 density was 52 micrograms per cubic meter, a 7.1 percent decrease from the same period last year.

The nation's air quality generally improved in the first four months but some regions witnessed decreases in air quality because of poor meteorological conditions (less rainfall, for example), industrial pollution and sandstorms, according to a center monitoring air pollution under the ministry.

Chai Fahe, the center's deputy director, said the average temperature in April was much higher than the previous April.

"Air pollution in April was different from that in the heating season. It was mainly caused by industrial pollution, not emissions from heating," he said. "Enterprises or factories that illegally discharge pollutants should be punished or restricted to secure a better environment with good air quality."

More than 200,000 cases of environmental contamination were filed in 2017, a year-on-year increase of 69 percent, with penalties reaching over 11 billion yuan ($1.72 billion), the ministry said on Tuesday at a law enforcement meeting in Chongqing.

Enforcement of laws against environmental pollution will be further strengthened in 2018, the ministry said.