Everywhere we go, we leave little traces of ourselves behind. The strand of hair, the wad of gum, the cigarette butt, nail clipping, or puddle of spittle. And all of these negligible bits and pieces that we so casually or unknowingly discard, contain our genetic information.

Doctoral student Heather Dewey-Hagborg, who is completing her degree in electronic art at Rensselaer Polytechnic Institute in Troy, New York, wanted to find out just how much of ourselves we are potentially revealing through this personal debris. So she began collecting these nasty little leave-behinds, and found that, “the more I walked around the city, the more I saw these genetic artifacts everywhere I looked.”

Heather’s next step was to take her collection of forensic samples to a community bio-lab in New York City for DNA analysis. She sequenced specific genomic regions and then crosschecked what she found against the published database on the human genome.

Meticulously focusing on approximately 50 human traits related to such characteristics as the color of hair, eyes and complexion, the propensity to carry extra weight, and an individual’s ancestry, Dewey-Hagborg was able to discern the likely physical traits of the former ‘owners’ of whatever it was she was sampling.

She fed the information into a computer and then used a 3-D printer to generate a mask that reveals what the person may have looked like. Though she couldn’t predict the actual shape of their face, this is not because the DNA from a strand of hair won’t reveal that kind of information. It’s only that the science hasn’t gotten quite that far yet.

In 2013, Dewey-Hagborg exhibited her masks in an art show she called ‘Stranger Visions.’ The exhibition at Genspace, the community bio-lab, will continue till mid-June – then on to Long Island and Mexico City.

Given that we’re now ‘under the protection’ of the surveillance state – such that police agencies are amassing an enormous database of our biomarkers – we might want to consider the wisdom of doing what our mothers always told us we should do. Doesn’t it make sense to pick up after ourselves – and avoid public spitting – rather than shedding valuable bits of information everywhere we go?

“You wouldn’t leave your medical records on a subway for just anyone to read,” Dewey-Hagborg said. “It should be a choice.” And that’s just what she is endeavoring to make it. She has developed a two-part product called ‘Invisible,’ which contains a bottle of Erase – to remove 99.5% of your genetic material – and one called Replace, to scramble the code on whatever remains.

Because she’s not in it for the money, Dewey Hagborg also provides the recipe for the DIY version of Invisible at her at http://biogenfutur.es web site. She also provides a very persuasive explanation of why this is a precaution worth taking in today’s world. As stated on her web site and in the brief intro video on the homepage, only .5 nanograms of DNA are necessary for analysis. Yet we leave 108 nanograms of DNA in a microliter of saliva.

You can learn more about Dewey-Hagborg at a hub for community research on biological privacy: biononymous.me. If you take the precautions that she and her associates advocate, you might end up – "doing things that might even border on illegal, but might be the same kinds of things that police or corporations might be doing less publicly," said. While pursuing her doctorate, Dewey-Hagborg is also an Associate professor of art at the School of the Chicago Art Institute.