Living in a haze

With smog dominating our life and headlines, sales of air purifiers and masks are flying off the shelves. Liu Zhihua explores how people cope with the pollution.

For 30-year-old Beijing resident Xu Qiong, the first thing he does after waking up every morning is to check the air quality index on his smartphone, and then decide whether to wear a mask.

He is not alone. That's the norm for many people in Beijing, Shanghai and many regions in China that are often covered by thick smog and haze.

The most severe spell lasted for more than 20 days in 17 provinces, municipalities and autonomous regions in early 2013.

Apps providing air quality index readings have mushroomed in the smartphone sphere, and products related to protection against air pollution, such as masks and air purifiers, are constantly sold out.

While people wait for wind and precipitation to clear the air, food that is rumored to fight against air pollution exposure, such as black fungus and pears, tops many people's shopping lists.

Some multinational companies have increased the hardship allowance of their employees. For example, Japan's electronic firm Panasonic recently announced to their staff members in China that they will be paid more to compensate for the air pollution.

"In the past, few had heard the term PM2.5 (particulate matter with a diameter smaller than 2.5 micrometers), but now many realize the risk of being exposed to PM2.5," says Zhang Shunan, director with the respiratory diseases department of China-Japan Friendship Hospital in Beijing.

The number of Zhang's patients increases during smoggy days.

Most of the patients are senior citizens and children, but there are more young people who suffer from coughs, asthma, sore throats and other respiratory illnesses, Zhang adds.

Scientists have long established that PM2.5, which forms haze and smog when dispersing through the atmosphere, is hazardous to people's health. There have been severe air pollution episodes in history, such as in London in 1959.

In influential medical journals, such as The Lancet and JAMA, there have been articles and studies on the health risks of exposure to fine particulate air pollution since the 1970s.

Unlike PM10, or coarse dust particles that can be filtered by the nose and expelled through the respiratory tract, fine particulate matters (PM2.5), often attached with viruses and microbes, can get into the lungs and enter the bloodstream, and then produce acute and long-term health effects. The individual particles are so tiny that they cannot be seen by the naked eye.

In 2013, the World Health Organization's International Agency for Research on Cancer classified air pollution as a leading environmental cause of cancer, placing it in the same category as tobacco, and UV and plutonium radiation.

A variety of other illnesses, including cardiovascular and respiratory diseases, such as stroke and asthma, are also linked to PM2.5 and PM10 exposure.

Xu, who has a 15-month-old son, says masks and air purifiers are essential to his life nowadays. Xu owns a 8,000-yuan ($1,304) imported air purifier.

Postings on how to choose a mask and air purifier are common on social media, and he decided on the particular brand of air purifier after long and thorough research.

He says his son is still so young, and he wants to give the toddler the best protection against air pollution.

A few days ago, when he got fined for violating traffic rules, he pitied the policeman instead of feeling sorry for himself, because it was a hazy day and the policeman was not wearing a mask.

It happened in February, when thick smog and haze persisted for more than a week in Beijing - the longest in duration since the capital started monitoring air quality in early 2012, and the air quality index stayed above 300 points for over a week.

An AQI reading above 200 points indicates the air is very unhealthy for people of all ages. When it goes above 300, it is hazardous, according to the United States Environment Protection Agency.

Purchases of masks in 2013 on Taobao.com, the country's largest online shopping platform, were 2.8 times higher than in 2012, and the purchases of air purifiers increased by 2.3 times.

But not everyone uses a mask correctly.

The material, structure and the method of wearing a mask are important, according to Li Guimei, the secretary-general of China Nonwovens and Industrial Textiles Association.

Ordinary cotton face masks are not designed to trap PM2.5, even though they can block large particles, says Li at an air-pollution protection forum held in Beijing in February.

Besides, as the domestic mask market is still developing, there is no nationwide official criteria and regulation on the categorization and use of different masks. As a result, many of the mask sellers claim their products are able to protect people from PM2.5. But they are made of materials that do not block PM2.5, or do not fit and seal the nostril and mouth areas, Li says.

Masks made of special materials - not just cotton - that have been confirmed to be able to block PM2.5, seal around the face tightly and do not have very big respiratory resistance are the best, Li adds.

As for air purifiers, sales increase in pace with growing awareness of PM2.5, but consumers may become confused on how to choose among so many brands and types, especially when there is no official criteria and testing method on an air purifier's ability to remove PM2.5 in the air, according to Wu Jixiang, an expert with Shanghai Jiaotong University.

A non-governmental consumer-rights protection organization in Shanghai reported in 2013 that almost all the air purifiers it tested exaggerated their ability to remove PM2.5, Wu adds.

Wu suggests customers seek advice from trustworthy professionals when choosing an air purifier, or use a hand-held PM2.5 measuring device to measure the efficiency of the machine. It is also important to follow the instruction of the user's guide to make good use of an air purifier, Wu adds.

Xu Qiong, the Beijing resident, says depending on masks and air purifiers to protect against air pollution are not long-term solutions. Instead, the government should take efficient action to clean the air as soon as possible.

Contact the writer at liuzhihua@chinadaily.com.cn.