Biomonitoring Summary


CAS No. 7440-46-2

General Information

Cesium is a silver-white metal that is found naturally in rock, soil, and clay. Inorganic cesium compounds are used in photomultiplier and vacuum tubes, scintillation counters, infrared lamps, semiconductors, photographic emulsions, and high-power gas-ion devices, and as polymerization catalysts. Radioactive 137Cs has been used medically to treat cancer.

Most human exposure to cesium occurs through the diet. For absorbed cesium salts, the body half-life is estimated to be 70-109 days based on 137Cs exposures. Little is known about the health effects of this metal, although cesium was generally of low toxicity when given to animals. However, cesium hydroxide is corrosive and irritating at high concentrations. Case investigations of ingestions of large doses of cesium chloride have reported decreased appetite, nausea, diarrhea, and cardiac arrhythmia (ATSDR, 2004). Human health effects from cesium at low environmental doses or at biomonitored levels from low environmental exposures are unknown. Workplace guidelines for cesium hydroxide are available from ACGIH and NIOSH. Whether cesium compounds are carcinogenic is unknown.

Biomonitoring Information

Urinary cesium levels reflect recent exposure. Two small studies of European populations reported urinary cesium levels similar to U.S. population results (Alimonti et al, 2005; Minoia et al., 1990). Using clinically submitted specimens, Komaromy-Hiller et al. (2000) found urinary cesium levels that were slightly lower than those reported for the U.S. population (CDC, 2012). Urinary cesium levels were similar in a group of forest fire fighters and residents living near the fire area (Wolfe et al., 2004), and were also roughly similar to those in the U.S. population (CDC, 2012).

Finding a measurable amount of cesium in the urine does not imply that the levels of cesium cause an adverse health effect. Biomonitoring studies on levels of cesium can provide physicians and public health officials with reference values so that they can determine whether people have been exposed to higher levels of cesium than are found in the general population. Biomonitoring data can also help scientists plan and conduct research on exposure and health effects.


Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological profile for cesium.2004 [online]. Available at URL: 10/26/12

Alimonti A, Forte G, Spezia S, Gatti A, Mincione G, Ronchi P, et al. Uncertainty of inductively coupled plasma mass spectrometry based measurements: An application to the analysis of urinary barium, cesium, antimony and tungsten. Rapid Commun Mass Spectrom 2005;19:3131-3138.

Centers for Disease Control and Prevention (CDC). Fourth National Report on Human Exposure to Environmental Chemicals. Updated Tables, 2012. [online] Available at URL: 10/26/12

Komaromy-Hiller G, Ash KO, Costa R, Howerton K. Comparison of representative ranges based on U.S. patient population and literature reference intervals for urinary trace elements. Clin Chim Acta 2000;296(1-2):71-90.

Minoia C, Sabbioni E, Apostoli P, Pietra R, Pozzoli L, Gallorini M, et al. Trace element reference values in tissues from inhabitants of the European community I. A study of 46 elements in urine, blood, and serum of Italian subjects. Sci Total Environ 1990;95:89-105.

Wolfe MI, Mott JA, Voorhees RE, Sewell CM, Paschal D, Wood CM, et al. Assessment of urinary metals following exposure to a large vegetative fire, New Mexico, 2000. J Expo Anal Environ Epidemiol 2004;14:120-128.

Page last reviewed: April 7, 2017