MCL: 5 pCi/L
Source: Contaminates water by erosion of deposits. Formerly used in luminescent paints.
Summary: Radium-226 is a naturally occurring isotope of radium, element 88 on the periodic table. It may form by radioactive decay of uranium and thorium. It has applications in radiation research and radiation therapy. It was formerly used in luminescent paints. Radium-226 has a half-life of approximately 1600 years and will decay to radon.