SHENZHEN ranks No. 3 in air quality between January and June among the 168 cities monitored by the Ministry of Ecology and Environment, according to a half-year report released Monday.

Haikou and Lhasa took the first two places, and Shenzhen was followed by Zhoushan, Huizhou, Huangshan, Zhuhai, Lishui, Xiamen and Zhongshan in the top 10 ranking.

Linfen, Xingtai, Shijiazhuang, Anyang, Handan, Taiyuan, Jiaozuo, Baoding, Jincheng and Linyi, most of which are in Hebei and Henan provinces, were the 10 cities with the worst air quality, the ranking shows.

Shenzhen has established an air quality monitoring system that covers 74 subdistricts across the city and reports PM2.5 concentration levels of the subdistricts on the app, mini-app and WeChat account of the Shenzhen environmental protection authority.

In May, Shenzhen’s average PM2.5 concentration, a key indicator of air pollution, stood at 16.9 micrograms per cubic meter, and the concentration in each subdistrict ranged between 12.6 and 23.0 micrograms per cubic meter, according to a report released by the Shenzhen environmental protection authority in June.

Shenzhen is the only city among the top 20 local economies in China that has met the national air quality standards in all six categories. However, compared to world cities such as London, Tokyo and New York, Shenzhen’s air quality still lags behind.

To narrow the gaps, the city government has unveiled Shenzhen Blue Sky Sustainable Development Action Plan, setting a target to reduce the average PM2.5 concentration year by year.

The city was awarded by the State Council in May for its achievements in pollution prevention and environmental protection last year.

By the end of 2018, Shenzhen had ranked among China’s top 10 cities for air quality for six straight years, becoming the only city in China among the top 20 GDPs with air quality that had reached such a standard in the past five years.

Before the end of 2019, Shenzhen will have built and expanded three sewage plants and upgraded nine plants, bringing its total waste water treatment capacity to 6.41 million tons a day.

Between January and June, the days with fairly good air quality in 337 prefecture or above level cities in China made up 80.1 percent of the total, up by 0.4 percentage points. A total of 142 cities reached the national air quality standards, 20 more than during the same period last year.

The average PM2.5 concentration was recorded at 40 micrograms per cubic meter, which is 2.4 percent lower than in the first half of 2018, as the average concentration of major pollutants like sulfur dioxide, nitrogen dioxide, inhalable particulate matter (PM10) and ozone continued to decrease.

(Han Ximin)