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How China's Pollution Sniffers Work

        Science | Green Science

To help combat the pollution that has resulted from China's modern industrial boom, an environmental monitoring station in the nation's Guangdong province is turning to an ancient method of detection -- the human sense of smell. Twelve trained professionals have spent their time in laboratories, exposed to a variety of noxious gases that plague the town of Panyu -- due to its plentiful factories and garbage dumps -- in an effort to detect scent profiles.

In this article, we'll learn about how the nose and the human brain detects and differentiates between smells, builds scent profiles or memories, and how scientists are using electronic devices and robots in artificial olfaction.

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Because of its current industrial boom, China is poised to become one of the world’s largest polluters.
Courtesy of Dan Eckstein/Picture China
Because of its large population and current industrial boom,
China is poised to become one of the world’s largest polluters.

In 2006, a World Bank pollution survey showed that, of the 20 most polluted cities in the world, 16 are in China. The pollution is taking a toll: more than 300,000 people in the increasingly industrialized nation are estimated to die each year from complications arising from poor air quality. Compounding this situation is the discovery of a much more deadly form of pollutant -- ultrafine particles. These particles are much smaller and more difficult to detect than other pollutants, have even more of a negative health impact as air quality worsens, and may even cause heart disease, among other health problems [Source: CNN].

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Liu Jingcai, the smelling team's leader and vice director of the monitoring station, told the China Daily newspaper that the training hasn't exactly afforded the team members a chance to use their olfactory skills to stop and smell the roses. "The work is quite unpleasant," said Liu. "We have to stay in a lab smelling those awful gases repeatedly [Source:China Daily].

Team members have been trained to distinguish between the smells of harmful environmental pollutants and simply objectionable, but harmless, odors. They have at their disposal sensitive electronic equipment (more on that coming up) that can detect the density of harmful gases in the air. But the Chinese sniffers have one distinct advantage over the machines: Humans can not only detect noxious gases, we can also display physical reactions to them, making the gases' presence in the atmosphere that much more apparent.

Since our sense of smell reduces in sensitivity as we age, the professional sniffing team will undergo recertification every three years to make sure its members still possess optimal smelling skills.

But as they walk around Panyu in search of pollutants, how exactly will the team be able to single out the smells they encounter? In the next section, we'll find out how the human brain sniffs out the differences.