Three environmental officials in northern China have been questioned by the police after air quality tests were allegedly doctored by putting cotton wool in the sampling equipment to filter out impurities, according to a newspaper report.
One official in Xian in Shaanxi province is also accused of manipulating air pollution data stored in a computer, the Huashang Daily reported.
Environmental protection officials around China are under pressure to take measures to improve air quality after the central government announced two years ago that it had “declared war on pollution”.
The allegations of fiddling test results have been made against the director of the Chang’an bureau of Xian’s environmental protection agency, plus the director and deputy director of the air sampling station in the district, according to the report.
The director of the air sampling station sneaked into the station several times to manipulate data on computer after the station moved to part of the Xian University of Posts and Telecommunications, the newspaper said.
The centre is also overseen by the China National Environmental Monitoring Centre and officials became suspicious after a sudden improvement in the quality of the data.
Surveillance footage shot at the Xian monitoring centre was also allegedly deleted as staff knew the watchdog would be visiting, according to the article.
A source with knowledge of the matter was quoted as saying that the director of the station may have feared punishment because of the poor quality of the data collected.
Measures taken to ensure the accuracy of air quality monitoring include sending data immediately to the national environmental monitoring centre.
Monitoring devices are also programmed to detect abnormal results and watchdogs visit sampling centres without advance warning to carry out checks, an employee at the Xian Environmental Protection Agency was quoted as saying.
More than one million Chinese people died from illnesses linked to air pollution in 2012, according to figures from the World Health Organisation.
The Chinese government has been stepping up its efforts to improve air quality in recent years, including setting up a no-coal zone in cities around Beijing next year in an effort to tackle the capital’s notorious smog.