Considering the role of COVID-19 pandemic in dropping average PM 2.5 concentration in major Chinese cities to 33 micrograms per cubic meter in 2020, the country's top environmental watchdog plans to set a target of keeping the average density this year in these cities only below 34.5 mcg per cubic m, a senior environmental official said. 

"Due to the impact from the pandemic, emission density has decreased," Liu Bingjiang, head of air quality management at the Ministry of Ecology and Environment, said at a news conference on Thursday. 

He said it seems the target will result in a setback in air quality. "If we deduct the contribution of the pandemic to the improvement, you will find the target still asks for continuous improvement in air quality," he said. 

The contribution of the epidemic for the improvement stands at 2 mcg per cubic m, Liu said, quoting research from the National Joint Research Center for Tackling Key Problems in Air Pollution Control.

For the 14th Five-Year Plan period (2021-25), the ministry plans to set a target of bringing down the average density of particulate matter by 10 percent, he continued. 

There was no general target for the pollutant's control during the 13th Five-Year Plan period (2016-20), but only one for those that failed to see the concentration reach the World Health Organization interim target 1 of 35 mcg per cubic m by the end of 2015. 

"Both the targets for this year and the one for the 14th Five-Year Plan period are positive. And it's not so easy to realize these targets. It needs a lot of arduous effort," he added.