Metabolism of Uranium in the Rat after Inhalation of Two Industrial Forms of Ore Concentrate: The Implications for Occupational Exposure

Abstract

<jats:p> Aerosols produced from two commercially available ore concentrates in which the uranium was present essentially in the one as ammonium diuranate (ADU) and in the other as uranium octoxide (U<jats:sub>3</jats:sub>O<jats:sub>8</jats:sub>) were administered to rats. The results show that: </jats:p><jats:p> 1 uranium in the ADU bearing material was cleared rapidly from the lungs, mainly to the blood, such that the retention kinetics were similar to those for a class D (highly transportable) compound as defined by ICRP; </jats:p><jats:p> 2 uranium in the U<jats:sub> 3</jats:sub>O<jats:sub>8</jats:sub> bearing material was removed from the lungs principally by mechanical processes, the retention kinetics in this case being similar to those defined for a class Y (poorly transportable) compound; </jats:p><jats:p> 3 for both materials the distribution of uranium amongst body tissues and the fraction of the systemic content excreted in urine were similar to those obtained after the injection of soluble hexavalent compounds; </jats:p><jats:p> 4 for workers potentially exposed to both these materials, urine monitoring and lung radioactivity counting measurements should be used in addition to air sampling procedures for assessing the intake of uranium. </jats:p><jats:p> 5 intakes of the ADU bearing material should be restricted to those permitted for short-term exposures on the basis of chemical toxicity, whereas those for the U<jats:sub>3</jats:sub>O<jats:sub> 8</jats:sub> bearing material should be governed by radiation dose. </jats:p>

Assessment Of Physico-Chemical And Biokinetic Properties Of Uranium Peroxide Hydrate UO4

“…The rapid fraction (34.7 to 43.5%) transferred to blood at 1 d is similar to the 39% measured for ADU (Stradling et al 1987), and 46% (Bailey et al 1998) for UO,. On the basis of these data, and in agreement with ICRP Publication 30 (1979) classification, UO, should be assigned to inhalation class D, since only a small proportion of the uranium, about 4%, has lung retention kinetics consistent with class W.…”

Uranium behaviour in the baboon after the deposition of a ceramic form of uranium dioxide and uranium octoxide in the lungs : implications for human exposure

“…The respective weights of the lungs were 79.4, 72.1, 69.6 and 58.6 g. Using the same method of calculation as above, the mass concentrations in the lungs were equivalent to respectively 4.5, 7.4, ~0.96 and ~ 1.1 times those predicted after the inhalation of 1 ALI of a class Y uranium compound. The relationships of the mass concentrations of uranium in the lungs vs the ALI after inhalation of an aerosol of AMAD 5 Jim would be similar to the values above, since the lower fractional deposition in the pulmonary region, about 10 %, would be largely offset by the greater value of the ALI under these conditions [15,23].…”

“…U 3 0 8 intakes by baboons were too low for the lung retention kinetics of uranium to be assessed with confidence by chest monitoring. The longterm retention half-time predicted for workers on the basis of Stradling's experiments with rats exposed to a similar U 3 0 8 preparation suggests it would be about 230 d [23,25]. The baboon data quoted in tables V-VII suggest that the amounts of uranium likely to be retained indefinitely in the thorax as a consequence of accumulation in the lymph nodes will be appreciably lower after inhalation of U 3 0 8 than after inhalation of U0 2 .…”

“…The evidence available suggests that the overall biokinetic behaviour of uranium in humans can be predicted reasonably accurately by combining data obtained on the translocation of uranium to blood in the rat with mechanical clearance data obtained from humans exposed to clay particles labelled with 85 Sr or 88 Y (Stradling et al) [23][24][25]. However, in order to assess uranium distribution between the lung and thoracic lymph nodes, and to investigate uranium concentration in various bones of the skeleton, a large primate such as the baboon is the most appropriate animal species.…”

Controlling intake of uranium in the workplace: Applications of biokinetic modeling and occupational monitoring data

“…Table 3.2. Leach et al 1973;Cook and Holt 1974;Pomroy and Noel 1981;Schieferdecker et al 1985;Price 1989;Stradling et al 1989b;Métivier et al 1992;Eidson 1994;Chazel et al 2000b;Ansoborlo et al 2002;Stradling et al 2002 Uranium West et al 1979;Eidson and Mewhinney 1980;Chalabreysse et al 1989;Stradling et al 1989aStradling et al , 2002Eidson 1990Eidson , 1994Métivier et al 1992;Barber and Forrest 1995;Ansoborlo et al 1998bAnsoborlo et al , 2002Chazel et al 1998 Uranium Stradling et al 1985Stradling et al , 2002Chalabreysse et al 1989;André et al 1989;Ansoborlo et al 1990Ansoborlo et al , 2002Eidson 1994;Chazel et al 2000a Uranium Galibin and Parfenov 1971;Cook and Holt 1974;Boback 1975;Eidson and Mewhinney 1980;Damon et al 1984;Stradling et al 1987Stradling et al , 2002Eidson 1994;Ansoborlo et al 2002 In vitro studies indicate dissolution rate varies with mixture of materials and preparation process. Differences found in dissolution rates of low-fired yellowcake (dried at less than 400° C) and high-fired (calcined) yellowcake (dried at 4...…”