MIT’s Technology Review has an article today on research that is underway to make extremely sensitive and rapid molecular sensors—aka “artificial noses”—that are so thin they could even be integrated into paper or textiles.

The use of particle detectors and chemical sensors to identify tiny amounts of chemicals or odors is an area that we’ve been keeping an eye on for a while—something we file under “possible future privacy-invasive technologies.” As Technology Review describes it, this technology

rapidly detects volatile organic compounds (VOCs)—gases in our surrounding environment that are produced by a wide variety of sources, everything from household paints to a person's own skin. Many do not have an odor, but an electronic sensor could alert a user to the presence of harmful chemicals or perhaps indicate that something is off-kilter with a user's health.

The main context in which Americans have encountered chemical sensors so far is in bomb detection—mainly at the airport when they or their belongings are swabbed and tested for traces of explosives. A “puffer machine” that blows air on passengers standing inside a booth was also tested for a while but found to be so far impractical for mass deployment. We’ve never had a problem with particle detectors; as long as they are tuned only to look for explosives, they do not raise substantial privacy concerns, as explosives are not something people normally have. (We have pointed out that there can be questions about their effectiveness, and the importance of treating people who “alarm” properly given that false negatives are probable.)

But such deployments may be only the beginning. Here are some other chemical detection efforts that we have seen already:

DHS has been working on a scheme to place chemical sensors in cell phones so that every American becomes a roaming chemical sensor able to alert the authorities to the release of chemical toxins resulting from accidents or terrorist plots.

Companies are selling sensitive drug-sniffing products that go way beyond breathalyzers, such as contactless hand-held scanners that claim to be able to detect trace amounts of drugs on virtually all surfaces, including skin and clothing.

DHS is also researching the use of body odor as a unique identifier or “odor fingerprint.” In theory, if that panned out, cheap and pervasive sensors could identify you everywhere you go.

As part of the same project, DHS is also researching their use “as an indicator of deception”—in short, they are pursuing that perennial chimera, a lie detector. While lie detection is a fool’s errand, it’s possible that odor detectors could reveal very crude facts about people’s emotional state.

Researchers are developing techniques for detecting medical conditions including cancer, asthma, and many other diseases by detecting “trace amounts of distinctive biomarkers in their breath.” (Sounds great in the hands of your doctor; used secretly during a job interview or bank loan application, not so much.)

Under a pilot program spearheaded by the White House’s “drug czar” in 2006, the government tested sewage from treatment plants in the Washington, D.C. area to measure the amount of trace cocaine that was present. This was done in an effort to estimate the level of drug use in those communities. It did not reveal anything about specific individuals.

The breadth of activity in this area makes it clear that if this technology continues to advance rapidly and becomes cheap and widespread as so many other technologies have in recent years, we will be facing an entirely new set of privacy issues. A whole new range of facts about ourselves (health conditions; emotional state; drug, alcohol and pharmaceutical use; our identity) could become open to unwelcome scrutiny by others (government, employers, insurance companies, nosy neighbors).

Sometimes such technologies get scary very fast; other times they don’t turn out to be a problem. We’ll be watching closely.