Uranium daily intake

Two-year feeding studies with uranyl fluoride, uranyl nitrate hexahydrate, uranium tetrafluoride, and uranium dioxide showed that chronic intake of large amounts of uranium can lead to a decrease in lifespan. The largest daily intake that did not affect longevity in the rat was 81 mg U/kg/day as uranyl... 

The uranium content of food has been studied extensively human daily intake has been estimated to range from 0.6 to 1.0 (0.9-1.5 ig/day) pCi/day of natural uranium. Uranium is adsorbed onto the roots of plants thus unwashed potatoes, radishes, and other root vegetables which retain their surface membrane are a primary source of uranium in the diet. Based on consumption rates, potatoes constitute the highest dietary intake of uranium (EPA 1985). One study showed that the concentration of uranium in plant roots was proportional to the uranium concentration in the soil (NCRP 1984a), while a second study did not support a linear relationship (Mortvedt 1994). 

Eisenne IM, Perry PM, Decker KM, et al. 1987. The daily intake of the uranium, thorium, and radium isotopes 234, 235, 238U, 228, 230, 232Th, and 226, 228Ra by New York City residents. Health Phys 53 357-363. 

The most important uptake route for uranium is ingestion of food and drinking water, as shown in Table 26.1-2 (see Chapter 26.1, Section 26.1.7). The daily dietary intake of U for Ukrainian males is estimated at 7.8 mBq (Shiraishik et al. 1997), with typical daily intake values being 0.16 Bq for 0.0005 Bq for U, and 0.16 Bq for U. Military use of depleted uranium led to inhalation during combat and to shrapnel contamination (Bleise... 

In general, the daily excretion of uranium will equal the daily intake. The urinary excretion will represent only a small fraction of the total elimination. Measurements of fecal excretion have been used to arrive at the total daily intake of uranium [22]. 

Ingestion of uranium contained in food and drinking water is the main route through which the general population is exposed to uranium compounds. The estimation of the average daily intake of uranium from food and drinking water based on several... 

Brazil In several studies, the uranium content in food products was determined and attempts were made to estimate the total average daily intake of uranium from food, usually excluding the contribution from drinking water. One study in Sao Paolo, Brazil, used fission track analysis (FTA) to estimate the mean daily intake of... 

Concentration of Uranium in Drinking Water of Residents of Southern Finland That Receive Their Water from Drilled Wells and Their Daily Intake of Uranium... 

Pakistan A stndy of the daily intake of uranium from food in a typical Pakistani diet used ICPMS for the analysis (Akhter et al. 2003). The range of daily intake was estimated to be 1.4-6.7 pg day with a geometric mean of 2.6 pg day. ... 

The biokinetic models estimate the half-life of uranium in the different compartments. Thus, for (rat) kidney the half-life has been estimated to be approximately 15 days, while for the skeleton half-lives of 300 and 5000 days have been projected, based on a two-compartment model (Wrenn et al. 1985). In another study using a 10-compartment model, half-lives of 5-11 days were estimated for the (rat) kidney and 93-165 for clearance from the skeleton (Sontag 1986). The overall elimination half-life of uranium under conditions of normal daily intake has been estimated to be between 180 and 360 days in humans (Berlin 1986). 

Estimates of absorption into the blood were derived from the excretion data of uranium mill workers (Wrenn et al. 1985). They estimated the daily mean absorption of inhaled uranium by mill workers at 24 pg U/day (0.34 pg U/kg for 70-kg reference man) based on measured excretion in feces and workplace ambient air concentrations. The absorption of uranium by these workers was estimated as 0.76% (range, 0.4-1.6%). Control subjects in a study of differential metabolism of °Th, and inhaled in uranium ore dust included 3 retired uranium mill workers (4—14 years since last employment as uranium ore crushermen), and 3 volunteers who lived in uranium milling communities but had no uranium work history. Two consecutive 24-hour urine and fecal collections were obtained and analyzed for and The apparent total intakes of uranium of these individuals ranged from 11 to 18 pg... 

An alternate method for estimating uranium intake is to measure the daily excretion of uranium in urine and feces. Using this method in a study of 12 subjects in Utah, it was estimated that the average dietary intake for the Salt Lake City population was 4.4 0.6 pg, an intake that is higher than that reported for New York City, Chicago, and San Francisco residents (1.3-1.4 pg) (Singh et al. 1990). 

Masuda K. 1971a. Intake and urinary excretion of uranium in non- occupationally exposed persons. I. Recovery of uranium in the daily diet and urine. Nippon Eiseigaku Zasshi (Japan) 26 434-437. 

There are two distinct situations for uranium exposure environmental and occupational. A population inhales and ingests fairly constant daily quantities of uranium from natural, local airborne, and dietary sources. This results in an equilibrium or steady-state condition for the intake and excretion of uranium. In the occupational circumstance, the quantity of the material, type of exposure (acute or chronic), exposure route, aerosol particle size, solubility class, biological half-times for elimination are some factors that influence the metabolic fate of the uranium. 

FIGURE 4.8 Daily uranium excretion by urine and hair as a function of daily uranium intake. (Measured concentrations are taken from Karpas, Z. et al., Health Phys. 88, 229, 2005b. With permission.)... 

Oeh, U., Priest, N.D., Roth, R, et al, 2007b. Measurements of daily urinary uranium excretion in German peacekeeping personnel and residents of the Kosovo region to assess potential intakes of depleted uranium (DU). Sd. Total Environ. 381, 77-87. 

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