In humans, radioactive strontium can cause bone tumors and, possibly, leukemia. Here Photo caption below Webb hadn't set out to clean up radioactive waste. Her work started with calcium, but led to strontium. She was, and still is, fascinated by the way certain plants take up and store calcium. Plants need a large amount of calcium for normal growth and development, but too much can kill them.
Plants have a tremendous ability to store calcium oxalate.
Some plants contain almost half as much calcium by weight as does an average human body, and all without a calcium-rich skeleton. Webb found a way to isolate bunches of calcium oxalate crystals from grape leaves and to study how they formed. Her work was reported in The Plant Journal. As she worked with calcium, Webb became aware of research that showed how strontium can mimic calcium in biological systems. She and undergraduate Christina Rinderle found that tobacco picks up strontium just as it does calcium.