Studies on the Hazard Involved in Use of C14

Basis for the ICRP’s updated biokinetic model for carbon inhaled as CO2

“…The 2004 model was based largely on biokinetic data for radiocarbon-labelled bicarbonate and, to a lesser extent, carbon dioxide, and the assumption of virtually identical biokinetics of carbon following its ingestion or intravenous injection as bicarbonate or inhalation as carbon dioxide. That assumption is based on comparative biokinetic data for carbon inhaled as carbon dioxide or ingested or intravenously injected as bicarbonate, and the fact that carbon dioxide and bicarbonate are largely carried in a common form (CO 2 -H -) CO 3 in blood (Skipper 1952, Winchell et al 1970, Meineke et al 1993. The assumption of identical biokinetics of carbon entering the body as bicarbonate or carbon dioxide was also made in the development of the model described in this paper.…”

“…Parameter values of the revised model are based on the following data sources: (a) biokinetic data for 14 C in healthy human subjects over a three-week period following inhalation of 14 CO 2 (Whillans and Johnson 1984); (b) observed kinetics of 13 C or 14 C in human subjects following administration of labelled bicarbonate (Winchell et al 1970, Irving et al 1983, Hoerr et al 1989, Barstow et al 1990, Elia et al 1992, 1995, Meineke et al 1993, Leese et al 1994, Saccomani et al 1995; (c) the time-dependent distribution and excretion of the carbon label in laboratory animals following administration of carbon dioxide or bicarbonate (Bloom et al 1946, Buchanan 1951a, 1951b, Brues and Stroud 1952, Skipper 1952, Buchanan and Nakao 1955, Joftes 1967, Shipley and Gibbons 1975, Sahlu et al 1988, Ram et al 1999.…”