Total releases were estimated to be between 1,100 and 5,400 tons from 1953 to 1989. The highest releases occurred between 1958 and 1970. Air concentrations and cancer risks were estimated for the releases. The primary way in which people living or working near the plant site could have been exposed was by breathing carbon tetrachloride. The primary health effect from exposure to carbon tetrachloride is increased risk of liver cancer.
Beryllium is a light, hard, grayish non-radioactive metal that is lighter than aluminum.
It can be found naturally in rocks, coal, soil and volcanic dust. At Rocky Flats, beryllium was used to make nuclear weapons components. In addition to the beryllium used to manufacture nuclear weapons parts at Rocky Flats, there were several nearby sources of the metal. Experimental animals exposed to beryllium and its compounds have developed cancer. Inhaling or breathing dust containing beryllium is the main way in which people could have been exposed.