Chinese Cities Are Under-Reporting Their Air Pollution Data, New Study Argues


Tom Hale

Senior Journalist

clockApr 22 2021, 17:34 UTC

Smog lingers over the Shanghai Financial Center. Image credit: iamlukyeee/

After sifting through air pollution reports from a bunch of large cities in China, two researchers came across some suspicious inconsistencies – which they say suggests some local governments in China are fixing their data.

As reported in the journal PLOS One, Jesse Turiel of Harvard University and Robert Kaufmann of Boston University looked at data from monitoring stations run by local governments and compared it to data from stations run by US embassies in five large Chinese cities. The data included hourly measurements of air concentration of fine particles known as PM2.5 collected between January 2015 to June 2017 in the cities of Beijing, Shenyang, Shanghai, Guangzhou, and Chengdu.


Between these two data sets, the researchers noticed significant inconsistencies between the levels of suspended particulates with a diameter of 2.5 microns or less (PM2.5) reported at certain hours – namely, the local Chinese stations were reporting lower PM2.5 levels than the US stations. A statistical analysis of the inconsistencies showed that they were too regular to be down to chance. 

The researchers conceded their whole study is based on the assumption that the US data was accurate. While this limitation should be held in mind, it’s worth noting that China has been accused of misreporting its air pollution data in the past. 

Some cities in China were previously synonymous with smog, but the East Asian powerhouse has been attempting to clean up its act over the past decades with some success. Even this study notes that local data misreporting does not invalidate results which that suggest urban air quality in China has largely improved in recent years.

As part of the push to rid their cityscapes of smog, the government introduced a series of policy reforms in 2012 that saught to reduce the misreporting of pollution data. This study, however, argues that those reforms were not foolproof. Local environmental agencies face a huge amount of political pressure to report pollutant concentrations that drop continuously year on year, with local authorities facing substantial penalties if their jurisdiction doesn’t meet targets. For a pen pusher working for these local authorities, it’s simply easier to misreport data. 


“Our findings of ongoing air quality data misreporting in China are not surprising, because the government’s post-2012 reforms did not eliminate incentives for local officials to cheat,” the study reads.

“This pressure is compounded by the fact that the central government has increased penalties for local cadres in failing cities without also increasing the flow of centrally-backed resources or financial support. Thus, faced with increasingly difficult attainment targets and a persistent lack of resources, some local officials have taken the path of least resistance by continuing to misreport air quality data,” they explain.


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