In December, Beijing issued its very first red alert over the levels of smog enveloping the city. The pollution reached such a point that officials took the decision to close many factories, keep children indoors, and limit the number of cars on the road. But to many it came as a surprise, as the level of pollution had beenmuch higherin the past, leading some to assume that it was a sign of the government taking more concern over the health of itspeople and theenvironment.
Yet now the Chinese state news agency Xinhua has reported that the city is to raise the threshold for issuingred alerts, which are the highest air pollution warnings. Many countriesuse the air quality index (AQI) as a measure of how much pollution isin the air.This looks at the concentration of solid and liquid particleslarger than 2.5 micrometers, known as particulates, in the air, as well as other harmful substances such asozone, carbon monoxideand sulfur dioxide. How countries measure the AQI varies from nation to nation.
The calculation of the AQI by Chinese authorities combines the measurements taken from all of thesepollutants to give a reading from zeroto more than 500. Back in December, a reading of over 200 for three days straight thatprompted the red alert. But now it will have to hit 200 for four days, be at over 300 for two days, or breach an AQI of 500 for one day before the city will issue an alert.
To some, this is an attempt by the government to limit the economic impact ofissuingred alertsby reducing them, as they result in people beingunable to go to work and limits on the number of cars on the road beingput into place. There will be multiple times of red alerts in a year if we continue using the current standards, which will bring about a high social and economic cost, Ma Jun, an environmental researcher in Beijing, told The New York Times.
During the last red alert, the city recorded the peak number of particulates in the air as 291 micrograms per cubic meter. The World Health Organization recommends that the level of these particulates should be limited to a 24-hour average of just 25 micrograms per cubic meter. So the fact that the Beijing has just made it harder for a red alert to be raised could be seen asworrying.
The new guidelines will not, however, only be in place for Beijing. They will also cover the surrounding industrial areas, including the major port city of Tianjin, which has a massive and rapidly expanding manufacturing industry. It is hoped,Xinhua claims, that these new rules might actually work to reducethe air pollution pumped out by the surrounding regions, whichcould have a positiveknock-on effect for the city itself.
Main image credit: LWYang/Flickr CC BY 2.0