Inset: People walk on a pedestrian overpass across a main road in Beijing on March 15. Photo: CFP

No matter what she did to try and protect her 3-year-old son from Beijing's notoriously serious pollution, such as taking him out of kindergarten, putting dozens of plants around the home, or spending huge amounts of money on air purifiers, Li Jing has had to admit that her efforts have been in vain.

One week after being "grounded," her son started coughing.

This year has seen record numbers of smoggy days around the country, with at least 10 out of 23 provinces issuing red alerts. With no sign of the air getting cleaner in the short term, residents like Li have been forced to find other ways to cope with the pollution.

"I learned how to cook soup for my family," she told the Global Times. "I found a recipe for dry vegetable soup that is said to prevent lung cancer."

This came in the wake of the World Health Organization (WHO)'s recent announcement that polluted air kills millions of people every year. A week ago, an 8-year-old girl became the country's youngest lung cancer sufferer. Doctors linked her disease with high levels of PM2.5, small particles less than 2.5 micrometers in diameter that can penetrate deep into the lungs.

The repeated news coverage of high PM2.5 levels has worried many residents and raised awareness of rising pollution levels.

"We leave it to the government to clean up the outdoor air, but we take responsibility for making the indoor air cleaner," Li said.

Indoor monitoring

Beijing has long suffered from air pollution. Heavy reliance on coal, millions of motor vehicles and dust storms from neighboring provinces have all contributed to the problem. Earlier in January, the capital city saw a record PM2.5 reading of over 600 micrograms per cubic meter, which was more than 30 times above the level judged safe by the WHO.

Last month, the city announced the toughest smog emergency measures yet: If the PM2.5 level exceeds 300 micrograms per cubic meter for three days in a row, schools would be suspended, construction sites ordered to halt work, private cars limited to using roads on alternate days and factory emissions cut.

With no sign that these measures could decrease the smog any time soon, many residents have started paying attention to the indoor air quality, as they usually spend up to 70 percent of their time either at home, in the office or in public areas.

Earlier this year, CCTV anchor Zhang Quanling posted on Weibo, China's version of Twitter, about her recent visit to the National Museum of China, saying she was surprised to find that the indoor PM2.5 level was only 16.

"I was shocked to find that the PM2.5 inside the museum was only 16, while outside it was almost 1,000," she wrote. "From now on, I will bring my family to the museum on polluted days."

Staff at the museum told the Global Times that the credit should go to their new fresh air filtration system, which is designed to protect the exhibits.

Many believe the best way of avoiding pollution is to stay indoors. So when the world's biggest shopping mall, the New Century Global Center - a building large enough to accommodate 20 Sydney Opera Houses inside - opened in Chengdu in September, some netizens were thrilled that they could free themselves from the air pollution. Shoppers there could even warm themselves under its round-the-clock artificial sun.

Normally, on a polluted day, children and elderly people are urged to stay indoors with their windows closed. However, some experts point out that the indoor danger is as prevalent as it is outdoors. Little research had been done on indoor air quality until last year. The Beijing Center for Disease Control and Prevention (CDC) launched a three-year project to study levels of indoor exposure to PM2.5 and its impact on people's health.

It said the project will analyze the air samples taken in different indoor locations including offices, schools, hotels and hospitals, and then study the correlation between the density of indoor PM2.5 and the external surroundings. The results will then be used to draft the city's public health policies.

Heightened awareness

One month after coming back to China from the US this August, 24-year-old Lucy Liu said she began experiencing symptoms such as irritation of the nose and throat and coughing.

"The doctor could not figure out what was wrong. After I told him I had just come back from the States, he said it was probably because of the pollution," Liu told the Global Times.

Liu is not the only one who feels under the weather. Last month, Grammy winner Patti Austin canceled her performance in Beijing after suffering an asthma attack. Many believe it was linked to the heavy smog that blanketed Beijing that day. Since then, Liu said she has started improving the air quality at home.

"That is probably the only thing I can do to help myself," she said.

There are many different kinds of particulate pollutants in homes and offices, including those from outside and those caused by indoor activities such as smoking.

"Our Chinese cooking styles also contribute a lot to PM2.5 density. We hope Beijing citizens cooperate with us and work with the government to clean the air," said Zhao Huimin, director of Beijing's Foreign Affairs Office, in an interview last month.

His remark soon triggered public anger as many believe the government is trying to shift the responsibility away from itself. Some netizens joked that the government could set up another lottery system to decide who can cook on what day, in an allusion to the way car license plates in the city are distributed.

"I didn't know cooking at home could increase PM2.5. Now I have to wear a mask when I cook," a Beijing housewife surnamed Zhao joked with the Global Times.

Worried that eating out might expose them to unsafe food and poisoned air, Zhao often cooks at home. Now it seems that cooking at home is not any safer, she has decided to upgrade her exhaust fan.

The desire for cleaner indoor air has become a new selling point for electrical appliances such as exhaust fans and air purifiers as the pollution worsens.

Electronics maker Sharp's sales doubled last year, making up about 30 percent of the company's sales of household electrical appliances in China, according to a Bloomberg report in February.

Chinese political cartoonist Biantai Lajiao, also known as "Rebel Pepper", who has been living in Beijing for a year, finally brought himself an air purifier. He posted on Weibo photos of water that turned black after it was cleaned, with many people commenting that they had the same experience.

"I feel better when I see monitors display the indoor PM2.5 level as good," he told the Global Times, adding that he wanted to leave the city badly earlier this year, but decided to stay and fight the pollution.

Understanding residents' concerns, the Shanghai Environmental Protection Industry Association announced last year that households could register for free PM2.5 testing in their homes. The program would cover 10,000 local families to study indoor PM2.5 levels and its effects on people's health, according to the association.

Fang Yunge, technology consultant of Beijing-based TianshengJiajing Environmental Monitoring and Assessment Co Ltd, told the Global Times that there has been an increasing number of requests to have these tests.

"An increasing number of urban families, especially those with children and the elderly, have greater awareness of the health benefits of clean air," Fang said.

Market impact

Cleaner indoor air has also become a major selling point for property developers and employers. Speaking at a forum on indoor air quality in May, Yu Qingxin, deputy director of the Beijing Property Management Association, pointed out that some office renters had asked for refunds due to the poor indoor air quality.

"It is the government's concern whether or not more and more companies will move out of Beijing, but for us it is devaluing Beijing's property," Yu said.

To attract more renters, developers such as the China World Trade Center, located in the heart of Beijing's central business district, have invested over 10 million yuan in improving the indoor air quality in its 540,000-square-meter Phase 3 Project in 2009.

The recent Galaxy Soho project, which is a mix of office and retail space operated by billionaire couple Zhang Xin and Pan Shiyi, has had air pollution control equipment installed.

"The reason why developers want to do this is because they have already sensed the need of the market, and it will eventually affect the value of their projects," said Zhang Ping, director of Cushman & Wakefield's Beijing research operations, a privately held commercial real estate services firm.

When it comes to the future of residents' individual war against PM2.5, many say that victory is still a long way away.

One of Rebel Pepper's cartoons portrays a couple walking hand in hand on a heavily polluted day. The woman asks, "I just bought a new dress today, do you like the color?" The man, who is wearing a gas mask, turns and looks at his girlfriend, able only to see her hand in the smog.

"Beijing's pollution is like the American horror movie The Fog. There might be a monster hiding in there, and it could hunt you down anytime," he said.