Shenzhen’s air quality improved last year, with fine particles, classified as PM2.5, at the lowest level in 15 years, according to the city’s environmental bulletin for 2018.
The average density of PM2.5, which are fine inhalable particles at a diameter of 2.5 micrometers or smaller, in the city was reduced to 26 micrograms per cubic meter last year, said Zhang Yali, vice director of Shenzhen Municipal Ecology and Environment Bureau, as he released the bulletin at a news conference Tuesday.
The city had 345 days with air quality ranked good (I) or fine (II), rising 0.5 percentage points higher than in 2017 to make up 94.5 percent of the year and ranking Shenzhen sixth out of 169 major cities in China. The city recorded two fewer smoggy days in 2018 as compared with the previous year. The primary pollutant was ozone, which accounted for 26 percent of the total air pollutants, followed by fine particles (22.4 percent) and nitrogen dioxide (22.1 percent). PM2.5 had been the primary pollutant in Shenzhen before 2015.
In light of such a change, Shenzhen’s air pollution control will begin targeting both ozone and PM2.5, rather than just PM2.5, said Lan Zijuan, a senior engineer with the bureau.
Overall water quality also saw an improvement, with the rivers flowing through at least two cities seeing a “historic turnaround.” The Shawan River and Futian River had much better water quality in 2018, while the Maozhou River and Shenzhen River saw a marked reduction in pollution. The Xinzhou River, Guanlan River and Pingshan River recorded slight alleviations in pollution levels.
The city’s noise levels were at a medium level last year while radiation levels remained safe, according to the bulletin.
A string of measures contributed to the improvement of air quality, according to the bureau. The city introduced more environment-friendly gasoline and diesel last year, and container vessels that docked at Shenzhen ports were required to use diesel with a lower sulfur content. Incentives to scrap old vehicles led to 129,000 cars with high emissions levels being retired or transferred out of the city. A total of 21,500 new all-electric taxis were put into operation, making the city’s taxi fleet completely powered by electricity. A technological upgrade at Mawan Power Plant has achieved lower levels of pollutant discharge, while the seven gas-fueled power plants in the city also underwent technological transformation, with the discharge of nitrogen oxide reduced to the lowest levels in the world.