U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Main content area

Temporal and spatial variations of air pollution across China from 2015 to 2018

Xiaoteng Zhou, Vladimir Strezov, Yijiao Jiang, Tao Kan, Tim Evans
Journal of environmental sciences (China) 2022 v.112 pp. 161-169
air pollution, air quality, coal, iron, steel, traffic, China
This study investigated concentrations of PM₂.₅, PM₁₀, SO₂, NO₂, CO and O₃, and air quality index (AQI) values across 368 cities in mainland China during 2015–2018. The study further examined relationships of air pollution status with local industrial capacities and vehicle possessions. Strong correlations were found between industrial capacities (coal, pig iron, crude steel and rolled steel) and air pollution levels. Although statistical and significant reductions of PM₂.₅, PM₁₀, SO₂, NO₂, CO and AQI values were observed in response to various laws and regulations in industrial sectors, both particle and gaseous pollutants still had annual average concentrations above recommended limits. In order to further reduce air pollution, more efforts can be done to control traffic emissions caused by minicars and heavy trucks, which was revealed after investigating 16 vehicle types. This was also consistent with the apparent air quality improvement during the COVID-19 lockdown period in China in 2020, despite industrial operations being still active at full capacities.