A thick wall of “off the scale” smog forced the delay or cancellation of more than 150 flights to and from Beijing on Tuesday, according to AFP:
The national meteorological centre said the Chinese capital had been hit by thick fog that reduced visibility to as little as 200 metres (650 feet) in some parts of the city, while official data judged air quality to be “good”.
But the US embassy, which has its own pollution measuring system, said on its Twitter feed that the concentration of the smallest, most dangerous particles in the air was “beyond index” for most of the morning.
The US system measures particles in the air of 2.5 micrometers or less, known as PM2.5, considered the most dangerous for people’s health.
Tuesday’s reading on its air quality index, which rates anything over 150 as unhealthy, over 200 as very unhealthy and over 300 as hazardous, breached the upper limit of 500, at which it stops giving figures.
Tensions over Beijing’s air quality rose in December following a string of similarly hazardous days, with residents demonstrating a heightened level of impatience over the government’s official explanation that heavy fog caused the poor conditions. Beijing’s Environmental Protection Bureau, whose official pollution readings of the larger PM10 particles have prompted skepticism, declared air quality to have reached a crisis level even as the China Daily reported on Monday that the amount of smaller and more dangerous PM2.5 had actually decreased over the past ten years. Readings from the U.S. Embassy in Beijing, reported hourly via Twitter despite demands from the Chinese government in 2009 to stop doing so, has differed greatly with and challenged the validity of Beijing’s data.
In response to recent public outcry, Beijing announced plans to publish more detailed air quality data last Friday. From The New York Times:
Beijing plans to publish hourly air quality reports based on an international standard known as PM 2.5, which measures tiny particles that are 2.5 microns or less in diameter, according to an announcement on the Web site of the Beijing municipal government. Those are the particles that are considered the most serious health hazard.
Big cities in China, including Beijing, generally publish air quality data that measure particles that are up to 10 microns in diameter. Using that standard has allowed Beijing to record more than 250 “blue sky days” during each of the past two years.
China’s Ministry of Environmental Protection also said early Saturday that monitoring pollution levels using the PM 2.5 standard would be included in a newly amended draft of national air quality standards, according to Xinhua, the state news agency.
Beijing’s air monitors have collected PM2.5 readings for the past five years, though the government never officially published any of the data. Now, in addition to Beijing, other Chinese cities such as Shanghai, Tianjin and Chongqing have also indicated intentions to begin publishing PM2.5 statistics this year. And while an expert warned the Guardian that there would be no quick remedy for the air quality in Beijing and elsewhere in China, Hong Kong-based journalist Frank Ching praised the announcement in The Globe and Mail today:
This is a huge victory not just for the U.S. embassy but for the Chinese people – a victory for openness, for transparency, for access to information and, most important, for public accountability over bureaucracy, for putting the health of the people over the face of government officials.
It’s natural for people to want information that affects their well-being. They will want that from any source, foreign or local. Of course, it would best if the Chinese government should supply this information rather than try to suppress it.
In principle, the more information that can be made available, the better. And a government that allows a free flow of information is a government that demonstrates confidence.
