Stable cesium is found naturally in small amounts in the soil, but it doesn't typically enter plants in large amounts. However, if it is radioactive, cesium can enter plants if it falls on their leaves, according to the Agency for Toxic Substances and Disease Registry. Under normal conditions, people consume very small amounts of stable cesium through the plants and animals they eat and the water they drink. Radioactive cesium is more of a concern. It can be found in foods produced in areas near nuclear accidents, such as the one that occurred at the Fukushima nuclear power plant in March 2011.
Potential for Cesium Contamination
In the United States, there isn't a need to be overly concerned about cesium in foods. The Food and Drug Administration checks shipments from Japan for radiation, especially those from areas near Fukushima. Less than 4 percent of the food imported to the United States comes from Japan. The foods most affected by the Fukushima incident include mushrooms, fruits, mountain vegetables, ginkgo nuts, chestnuts and seafood, according to a study published in 2013 in the "Journal of the Food Hygienic Society of Japan." Any of these foods from Japan may contain some cesium.
