Silicon Wristbands Help to Track Everyday Exposure to Pollutants

A team of scientists from Oregon State University has hit upon a novel, non-intrusive method of measuring everyday exposure to a whole host of harmful chemical pollutants. The team, led by environmental chemist Kim Andersen, has developed an easy-to-wear silicon wristband which is able to absorb chemicals as the wearer goes about their daily business.

After use, the wristband is then sent to the lab, where it can be analysed using gas chromatography (GC). This analysis allows researchers to identify the host of contaminants the wearer has been exposed during the time they wore the wristband.

How it works

The wristbands are a convenient and effective alternative to other methods of measuring air pollution, which can be cumbersome (backpacks) or gender specific (necklaces). The wristbands are comfortable to wear, androgynous and unobtrusive, even during activities such as sleeping, exercising or showering.

The wristband is composed of a complex set of silicon polymers, which are made of long molecules structures in the form of extended chains. The channels created by these chains are similar in size (roughly one nanometre) to the pores of human cell membranes, which means that they also act in a similar way in catching organic chemicals.

After use (one day, one week or one month), the wristband is sent away to the lab, where GC-MS is used to identify a range of different chemicals present on the sample. The technique is capable of detecting thousands of chemicals compounds in total, but the most prevalent ones appear to be pesticides, fragrances, flame retardants, polycyclic aromatic hydrocarbons (PAHs), endocrine-disrupters and polychlorinated biphenyls.

Applications of the band

The band was recently tested by Andersen and his team in a study of 92 pre-schoolers in the state of Oregon, who wore it for one week and produced startling results. Many of the test subjects showed exposure to polybrominated diphenyl ethers (PBDEs) — which have banned in the States for some time — as well as organophosphate flame retardants which have replaced PBDEs in many applications.

Such a study is not the only time that the silicon wristband has been called upon. In fact, since Andersen and his colleagues first reported the idea in 2014, a whole host of projects have taken advantage of its convenience and effectiveness.

Though the idea is still a fairly new one, it could represent the future of air quality and contamination monitoring. At present, the data is only qualitative, not quantitative — meaning it can detect which substances are present on the wristband, but not in what amounts — but this is something the team plan to work on in the future.

Alongside personal monitoring devices, it is recognized that quicker analyses are important too. This is a topic addressed in this article, The Need for Speed Applying Triple Quadrupole MS in Pesticide Residue Analysis Fast Pesticide Residue Analysis in a complex matrix using Triple Quadrupole Mass Spectrometer that looks at the latest technological developments.