Thick, off-the-scale smog shrouded eastern China for the second time in about two weeks Tuesday, forcing airlines to cancel flights because of poor visibility and prompting Beijing to temporarily shut factories and curtail fleets of government cars.

The capital was a colorless scene. Street lamps and the outlines of buildings receded into a white haze as pedestrians donned face masks to guard against the caustic air. The flight cancellations stranded passengers during the first week of the country's peak, six-week period for travel surrounding the Chinese New Year on Feb. 10.

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The U.S. Embassy reported an hourly peak level of PM2.5 — tiny particulate matter that can penetrate deep into the lungs — at 526 micrograms per cubic meter, or "beyond index," and more than 20 times higher than World Health Organization safety levels over a 24-hour period.

Liu Peng, an employee at a financial institution in Beijing, said he will keep his newborn baby indoors.

"It's really bad for your health, obviously," Liu said. "I bike to work every day and always wear a mask. The pollution in recent years is probably due to the increase in private cars and government cars."

Visibility was less than 100 yards in some areas of eastern China, the official Xinhua News Agency reported. More than 100 flights were canceled in the eastern city of Zhengzhou, 33 in Beijing, 20 in Qingdao and 13 in Jinan.

Every year, China's transport system bursts at the seams as tens of millions of people travel for the Lunar New Year holiday, in the world's largest seasonal migration of people.

Ren Haiqiang, a bank worker in his early 30s, said he had booked tickets to fly out of Beijing on Thursday to visit family in the coastal city of Dalian, but now worried about flight cancellations.

"Traveling over the holiday is already a huge hassle, along with all the gift-giving and family visits. We thought flying would be the best way to avoid the crush, but if the weather continues like this we'll be in real trouble," Ren said as he waited in line at a bakery in downtown Beijing.

Beijing's city government ordered 103 heavily polluting factories to suspend production and told government departments and state-owned enterprises to reduce their use of cars by a third, Xinhua said. The measures last until Thursday.

Beijing's official readings for PM2.5 were lower than the embassy's — 433 micrograms per cubic meter at one point in the afternoon— but even that level is considered "severe" and prompted the city government to advise residents to stay indoors as much as possible. The government said that because there was no wind, the smog probably would not dissipate quickly.

Patients seeking treatment for respiratory ailments rose by about 30 percent over the past month at the Jiangong Hospital in downtown Beijing, Emergency Department chief Cui Qifeng said.

"People tend to catch colds or suffer from lung infections during the days with heavily polluted air," he said.

Air pollution has long been a problem in Beijing, but the country has been more open about releasing statistics on PM2.5 — considered a more accurate reflection of air quality than other pollutants — only since early last year. The city hit its highest readings on Jan. 12, when U.S. Embassy readings of PM2.5 reached as high as 886 micrograms per cubic meter.

Celebrity real estate developer Pan Shiyi, who has previously pushed for cities to publish more detailed air quality data and who is a delegate to Beijing's legislature, called Tuesday morning for a "Clean Air Act." By late afternoon, his online poll had received more than 29,000 votes, with 99 percent in favor.

On Monday, Wang Anshun was elected Beijing's mayor after telling lawmakers the municipal government should make more efforts to fight air pollution, according to Xinhua.

Last week, he announced plans to remove 180,000 older vehicles from the city's roads and promote government cars and heating systems that use clean energy.

BEIJING — Air quality in Beijing was the "worst on record" on Saturday and Sunday, according to environmentalists, with pollution 30-45 times above the recommended safety levels.

With a thick smog wrapping the Chinese capital since Friday, the city's pollution monitoring center warned the city's 20 million residents to stay indoors.

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Data posted on Sunday by the monitoring center showed particulate matter measuring less than 2.5 micrometers in diameter (PM2.5) had reached more than 600 micrograms per square metre at some monitoring stations in Beijing, and was as high as 900 on Saturday evening.

The recommended daily level for PM2.5 is 20, according to the World Health Organisation. Such pollution has been identified as a major cause of asthma and respiratory diseases.

"This is really the worst on record not only from the official data but also from the monitoring data from the U.S. embassy — some areas in (neighboring) Hebei province are even worst than Beijing," said Zhou Rong, climate and energy campaigner at Greenpeace.

The Beijing Municipal Environmental Monitoring Center said heavy pollution had been trapped by an area of low pressure, making it harder to disperse, and the conditions were likely to last another two days.

Related: Beijing's pollution could cut 5 years off life span

Pollution has been identified as one of the biggest challenges facing China's leaders, with outgoing president Hu Jintao saying during his address to the Communist Party Congress last November that the country needed to "reverse the trend of ecological deterioration and build a beautiful China."

China said at the end of last year that it would begin releasing hourly pollution data for its biggest cities.

Beijing has already committed to a timetable to improve air quality in the city, and has relocated most of its heavy industry, but surrounding regions have not made the same commitments, said Zhou.

"For Beijing, cleaning up will take a whole generation but other regions don't even have any targets to cut coal burning. I bet the pollution here is mainly from those surrounding regions." 

 

BEIJING — Earlier this month, a U.S. study on the economic impact of China’s air pollution was released with little fanfare. Maybe it was because of the series of successive “blue sky” days we were enjoying in the Chinese capital, thanks to the gusty winds blowing down from Mongolia. 

The study, which was conducted by researchers at the MIT Joint Program on the Science and Policy of Global Change, breaks down costs that result from the health impacts from ozone and particulate matter, which typically lead to respiratory and cardiovascular diseases.

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The conclusion? “[D]espite improvements in overall air quality,” the cost of air pollution (as in lost economic productivity growth) in China has mushroomed from $22 billion in 1975 to $112 billion in 1995. But for at least one pair of 29-year old software engineers in Beijing, air pollution has actually meant greater economic productivity and a business opportunity.

A killer app
Wang Jun and Zhang Bin each moved to Beijing in 2001 to attend college.  Zhang, a Fujian native, was a math major at Beijing University while Wang left Inner Mongolia to study traffic infrastructure at Jiaotong University.

They met at a high-tech company, where for three years they worked together. Last year, they decided to strike out on their own and set up Fresh Ideas Studio.

“The primary aim … is creating mobile apps for solving practical problems in our daily lives,” Wang said, on a blustery (but sunny) afternoon at a coffee shop.

Last year saw some of the worst air pollution in Beijing since the 2008 Summer Olympics, spurring intense discussion among Chinese residents, teeth-gnashing among Western expats, and a near-diplomatic spat between the U.S. and China over fine particulate matter in the air known as PM2.5 that can wreak havoc on the respiratory system.

“Recently, the media and Weibo [a popular Chinese microblog like Twitter] users are very concerned about air quality, especially in Beijing,” Wang said.

In particular, there was a lot of online chatter about @Beijing Air, the U.S. embassy Twitter account that posts hourly Air Quality Index(AQI) data. 

The readings come from an air quality monitor that sits on top of the embassy in downtown Beijing, and they differ sharply from the daily results posted by the Ministry of Environmental Protection (MEP).

AQI values on @BeijingAir range from 0 to 500.  A “good” AQI  is 0 to 50 or what the Chinese call a “blue sky” day.  Unfortunately, many days in 2011 qualified as “unhealthy” to “hazardous.”  But on some of those same days, MEP data maintained the levels were “good” or “moderate.”  (The Chinese, in fact, claim there were 286 "blue sky" days in 2011.)

“The [Beijing] government says that nearly 80 percent of the days in the last two years met at least the Chinese standard and therefore had good or even excellent air quality,” Steve Andrews, an environmental consultant who has analyzed the @BeijingAir data, said. “While when we look at the U.S. Embassy data … over 80 percent days exceeded what would be considered healthy air quality and more days were hazardous than good.”

Andrews said that Beijing's pollution levels were "six or seven times higher than the U.S.'s most polluted city." "Air pollution at these levels likely shortens life expectancy by about five years," he added.

The discrepancy was due to the fact the U.S. embassy monitor includes PM2.5, a fine particulate matter measuring 2.5 micrometers in diameter that, according to the EPA, “pose the greatest health risks [and] can lodge deeply into the lungs.”

The Chinese data, however, only measured the much coarser PM10 particles.

“I’m a Twitter user and saw many Tweets about [@BeijingAir],” Zhang said. “Many Weibo users reposted the data, too.”

The software developers decided to try creating a smartphone application that based itself on the @BeijingAir data.

“Sometimes we can tell there’s a gap between what we feel and the data from the government,” Wang said.  “This is probably why many prefer the data provided by the U.S. embassy.”

In November, they released a 1.0 version, available only in Chinese and which came with simple but appealing graphics.  On good AQI days, the screen background was light and featured a hiking boot, indicating it was time to be outdoors. On bad AQI days, the screen background turned dark, an X marked the boot, and a person’s face wrapped in a mask would pop up.

There were iOS and Android versions of the app. Within weeks, it had been downloaded 80,000 times. At least half of those users checked the app regularly, according to Wang. 

Pollution 'ignored' in past
Under popular pressure that has been building since last year, Chinese environment authorities in Beijing have agreed to publish PM2.5 data. But they maintain the air quality has improved steadily in recent years. 

“We may have had bad pollution in the past, but people probably didn’t pay too much attention to it before so it was just ignored,” said An Xinxin, who works in the Automatic Monitoring Office at the Beijing Environmental Protection Monitoring Center. 

The Center relies on anywhere from 30 to 40 monitoring stations. “Almost every district and county in Beijing has its own station,” explained An. “So citizens in every district and county can know what the pollution in their own area is like.”

Like many of his colleagues at the municipal level, An pointed out that the U.S. embassy only uses one monitor. “[It] can only represent one spot at a certain time. Their spot might be very close to the road where there is a lot of vehicle exhaust, which causes a high level of PM2.5,” he said. “Our statistics are an average of Beijing as a whole, not just one spot.”

Zhang has lived in Beijing for more than ten years, but he said he’s not sure whether the air quality has improved or not. “I don’t know if it’s because now I pay more attention [because of the media and online discussion], or if it’s because the air quality has worsened,” he said. 

But he and Wang dreamed up the idea of incorporating both the Chinese and American data streams into their app.

On Monday this week, they introduced a 2.0 version that not only posts real-time data from the U.S. embassy in Beijing and U.S. consulates around China, it also includes data from the Chinese Ministry of Environment’s monitoring centers in 120 cities across the country.

Also available in English, the app has been downloaded nearly 5,000 times.

“We thought it was good to include both. In some cities, users might want alternative information,” Wang said. “If there were a third source for air pollution data, we’d probably include it in the app, too.”

They might also want to add Hong Kong to their list of cities.

This month, a local nongovernmental group said Hong Kong’s air is 20 per cent more deadly than the air in mainland China. 

Using data from Hong Kong’s own government and the World Health Organization, the Clean Air Network ranked Hong Kong ahead of mainland China, India, Vietnam, and Bangladesh for its high air pollution mortality rates.

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With additional reporting from Bo Gu and Ting Zhao.