There has been much comment on the clear skies this year in Nanjing, with good reason. Data just released shows that 2020’s average daily level of PM2.5 is as low as 37.7 micrograms per cubic metre (µg/m3), making Nanjing the cleanest city in Jiangsu province.
The newly-released figure is correct as of 16 May, according to the Provincial Department of Eco-Environment. Not only does this put Nanjing at number 1 in Jiangsu in terms of air quality, it is also the lowest PM2.5 figure achieved since monitoring began.
The data also represents a decrease of 30.4 percent on the same period last year. While undoubtedly influenced by significantly less economic activity on account of Covid-19, it’s worth remembering that we have now spent more time this year without the epidemic than with it. Putting the fall in PM2.5 down to Covid-19 alone belies the bigger picture; Nanjing’s air has been getting cleaner for many years now.
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After the peak in pollution in 2013, caused in large by Nanjing readying itself for the following year’s Youth Olympics, PM2.5 has declined every year since. 2015 saw the biggest drop, with the average concentration in built-up areas falling by 23 percent. In 2016 it fell another 16.3 percent, and in 2017, there was another drop of 16.7 percent.
For 2019, PM2.5 fell 3.4 percent on the previous year, to 39.9 µg/m3, reports Nanjing Daily.
Sitting in a kind of bowl, it’s tough to keep Nanjing’s air clean.
Nanjing is surrounded by mountains on three sides, meaning air, polluted or otherwise, has little chance to escape. Nanjing’s dirty air, meanwhile, has four primary sources; industrial pollution, transportation pollution, dust pollution and ozone pollution. As such, last August, the Municipal Party Committee and the Municipal Government issued the “40 Atmospheric Controls” (大气管控40条).
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This year, the environment was near the top of the city’s to-do list as the government got back to work in the wake of the epidemic. On 7 March, Nanjing Municipal Party Secretary, Zhang Jinghua, chaired a meeting setting out 2020’s ecological and environmental protection work, at which tackling ozone pollution was identified as a key task. The 40 Atmospheric Controls shall continue to be implemented, with particular focus on controlling emissions from the burning of coal and cooking oil, while strengthening dust control on construction sites.
This year to date, a number of key measures have been put in place for the reduction of Volatile Organic Compounds (VOCs) and nitrogen oxide in Nanjing’s air, including;
- Sintering machines reconfigured for ultra-low emissions
- Gas boilers reconfigured for low nitrogen emissions
- Creation of a VOCs governance compliance zone
- Removal and/or restrictions of vehicles with heavy-duty emissions (China III)
- Removal of black-market petrol stations
- Increased road cleaning and water spraying thereof
- Inspections on the production and sale of paint; the use thereof in industry and construction
Speaking on 27 March, Nanjing Mayor, Han Liming, emphasised that the city must build “ecological sustainability” (生态可持续) into its competitiveness.
