How China's Pollution Sniffers Work

The Effects of Pollution Sniffing

Most of us aren't paid to detect pollutants with our noses. We generally learn about the smells of our environment through casual exposure over time. But the Chinese government's approach to training its sniffers is more aggressive and focused. By exposing the team members to the smells in a lab over long periods of time, the sniffers' ideas of a smell become refined more quickly, similar to a wine connoisseur detecting the notes, or scent profiles, of a glass of Chardonnay.

Although humans have an incredible olfactory system, prolonged exposure to harmful to chemicals can lead to disease and death.
Courtesy of Chris Harvey/
The human olfactory system
is highly sensitive to chemicals
and pollution.

The Northwestern researchers showed that this kind of exposure creates a more sophisticated sense of smell for scents in the same family. Prolonged exposure also creates a more intense reaction to a smell. For example, if the Chinese sniffers had been exposed to sulfur for long periods of time, it would be easier for them to tell the difference between different types of sulfuric compounds. In turn, this would make them better at their jobs.

But sniffing sulfur and other noxious chemicals can be extremely harmful to the health of human beings. So, while the Chinese are employing humans to find pollution, scientists in other parts of the world are looking to technology in the form of electronic instruments.

Dr. Ricardo Araneda
­HowStuffWorks would like to thank Dr. Ricardo Araneda at University of Maryland for his help with this article.

The elephant in the room concerning the Chinese pollution sniffers is that those sniffers are humans. This means that their work will encounter two problems. The first is that their sense of smell will deteriorate over time. The second is that they inhale harmful chemicals for a living. The first problem can be overcome by recruiting replacement sniffers, but the second problem could lead to health issues and even death for the sniffers.

In the next section, we'll look at how robots and electronic devices are being used in artificial olfaction.