Radiation dosimeters are commonly used by clinicians working around CT scanners, fluoroscopes, radiotherapy systems, and other equipment. Typically, after wearing one for a month or so, the detector is sent to the manufacturer and the results come about a week or two later, though real-time smart countersare coming out. All these counters are also pricey, so there’s real demand for cheap dosimeters that can give rapid results without having to mail anything. Scientists at Purdue University have now developed special yeast-powered badges that can tell a worker exposed to radiation whether the dose has been too great or not.
The badges have live yeast cells within them, but they lay dormant until a reading needs to be taken. To do that, they’re simply dipped in water to activate the yeast, which begins to eat nearby glucose and flatulate out carbon dioxide. Since yeast cells are sensitive to ionizing radiation, exposure kills some number of cells and the stronger the dose the more yeast will die off. After the badge is dipped in water and allowed to do its thing, ions, in concentration proportional to the amount of living yeast, come up along with the carbon dioxide. The electrical conductivity of the yeast changes in the presence of the ions, and this change can be detected using simple electronics.
The badges don’t have their own readout yet, so they have to be put into a special device that does the measuring of the conductivity. Nevertheless, this is easier and cheaper than sending out a dosimeter, and the results are available the same day.