Air pollution in China: Status and spatiotemporal variations

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Public Health

Background:

• China experiences persistent air pollution linked to urbanization and climate change.
• Air quality data from over 1300 sites (2014-2016) were analyzed to assess pollution severity.
• Key pollutants include particulate matter (PM2.5, PM10) and gaseous pollutants (SO2, NO2, CO, O3).

Purpose of the Study:

• To analyze the severity and trends of air pollution across China from 2014 to 2016.
• To compare air pollutant concentrations between Northern and Southern China.
• To identify the impact of different pollutants and inform public health strategies.

Main Methods:

• Utilized three-year time-series concentration data for major air pollutants.
• Calculated annual population-weighted-average (PWA) values for different regions.
• Assessed population exposure based on Chinese Ambient Air Quality Standards-Grade II.

Main Results:

• Significant portions of the population lived in areas exceeding air quality standards for PM2.5, PM10, NO2, and SO2.
• Northern China exhibited substantially higher PWA concentrations for PM2.5, PM10, NO2, and SO2 compared to Southern China.
• Despite general improvements, wintertime PM2.5 pollution worsened, particularly in Northern China, and PM/O3 co-pollution emerged as a threat.

Conclusions:

• Air quality in China shows improvement, but challenges like worsening winter PM2.5 and complex PM/O3 pollution persist.
• NOx controls are more effective than SO2 controls for improving annual PM air quality in specific regions.
• Further epidemiological studies are crucial for assessing multi-pollutant health impacts and revising air quality standards.