On a "blue-sky day", this tourist would have a clear view from the top of a hill in Jingshan Park in Beijing. But on Monday, visibility was less than 1 kilometer. (Photo: China Daily)
"Fog is not pollution," Du Shaozhong said in his micro blog on Monday morning, in response to a question about Beijing's poor air quality.
It was the third consecutive day of hazy weather, with visibility less than 1 kilometer. And it was the third time in a month that the capital was blanketed in thick smog.
"In Chinese we usually say a fairyland is wreathed in fog. How can it be a fairyland if it is surrounded by pollution?" asked Du, deputy director of the Beijing Environmental Protection Bureau. "But it is true that fog can trap pollutants, which will affect air quality."
The official rating for air quality by Du's bureau on Monday was "slightly polluted" with inhalable particles.
Du blamed stagnant weather conditions - light wind and low atmospheric pressure - a situation not uncommon for Beijing when seasons change.
"At such points, we still have to rely on natural conditions to clear away pollutants, considering we have such a large scale of pollution emissions in the city and a limited environmental capacity," he said.
Beijing residents responded with their views on the air quality through Weibo, a micro-blogging website operated by Sina Corp. Some posted photos of buildings blurred by the thick haze, and some said they feel choked by the smoky air.
"It's like walking in a huge chimney, or having countless people keep puffing secondhand smoke at you - all the time," Yanhanyh wrote on Weibo.
"I don't believe the air is only 'slightly polluted' today. I started to cough after 10 minutes' walk in the open air, and I don't even dare to let my kid go out," said another Weibo user, Dapeng.
By Tuesday night, a little drizzle had begun to refresh the city, but stronger winds and rains are still needed to clear up the haze.
A public trust crisis is spreading over the official readings of Beijing's air quality, especially when some residents find alternatives that are more in line with their own senses.
PM2.5 the culprit
The US Embassy in Beijing has reported its own monitoring of air quality hourly since 2008. The readings are for ozone and for the concentration of PM2.5, the tiny airborne pollutants that cause haze and can travel deep into the lungs and damage people's respiratory systems.
Particulate matter currently measured in China is smaller than 10 microns and is known as PM10, while matter smaller than 2.5 microns is called PM2.5.
Tang Xiaoyan, a professor at Peking University's College of Environmental Sciences and Engineering, said research shows that Beijing's haze is caused mostly by PM2.5. The contribution of larger matter "is rather limited", she said.
As a result, readings from the US Embassy usually paint a gloomier picture than the official ratings from Beijing Environmental Protection Bureau. For Monday, the embassy report described the PM2.5 reading as "hazardous", the worst ranking on the pollution scale according to US standards.
The embassy's reports are posted automatically to twitter.com/beijingair. Accountant Wang Changyu, 32, receives the updates through an iPhone app called Beijing Air Quality, developed by SolarJoke, a Chinese programmer.
"I know the readings from the US Embassy may not reflect the overall air quality of Beijing accurately, but I am feeling very uncomfortable about the air," he said. "I try not to check the updates often because it really makes me feel depressed."
Du dismissed the accuracy of the pollution information on Monday, saying the US Embassy has made it clear that the monitoring is only for internal reference.
Seeking protection
Even so, some Beijing residents are seeking ways to protect themselves from the pollution, at least for psychological relief. Wang said his company started to distribute face masks Tuesday morning and encouraged employees to wear them when they go outside.
Yang Jiachuan, 34, a consultant at an accounting firm, recently spent 18,000 yuan ($2,800) to install a ventilation system to improve indoor air quality at home.
"I have never seen so many hazy days before. Beijing's fall used to be my favorite time. But now, it is totally different," Yang said.
Continual poor air quality has boosted business for Guo Kai, who sells indoor air purifiers in Changsha, Hunan province. His company's sales volume for Beijing rose 30 percent during the past month, Guo said.
"I've seen lots of discussion about air quality on micro blogs, and wanted to share my opinion as an industry insider," he said. Now he answers questions online - not only about his own products, but also types of masks for purchase, a protection many people turn to in outdoor activities.
Luo Yin, mother of a 4-year-old boy, started shopping online for masks after she read about the US Embassy's Beijing air quality report.
"I forbid my kid to play outdoors these days," she said. And she told him to wear two masks to school. "I hate to wear the mask as it ruins my makeup, but I definitely want to make sure that my kid is safe from the pollutants in the air."
Olympic gains
Beijing says it has recorded increasing numbers of "blue-sky days" - those with good air quality - every year in the past decade, but some residents are worried that the capital's air quality has deteriorated since the 2008 Olympic Games.
Yang, the accounting consultant, said she was impressed with the blue skies then. "But obviously not much of those improvements in the air quality were maintained. I'm wondering whether the neighboring factories have stopped their environmental protection measures," she said.
Beijing adopted rigorous pollution controls leading to the Olympics. More than six months before the Games, the capital's biggest polluter - a large-scale iron and steel plant - was moved out of the city. All factories in six surrounding provinces were asked to halt production.
Encouraging more use of public transportation, the city also invested heavily to upgrade its subway systems and bus services. It also took half of its vehicles off the roads for three months.
The result was satisfying. Beijing enjoyed beautiful days during the Games, and the model was copied by other cities hosting big international events, such as the Shanghai Expo and Guangzhou Asian Games. The measures also were celebrated by China's environmental watchdog as an effective cure for regional air pollution.
