Inhalation uranium

Figure 2-1. Levels of Significant Exposure to Uranium - Inhalation (cont.)... 

Other Systemic Effects. Several general effects have been attributed to uranium inhalation exposure. In animal studies, dogs exposed to 13 mg U/m as uranium hexafluoride for 30 days exhibited decreased water intake (Spiegl 1949). Reduced food intake was also observed in a 4-week study of rats and mice exposed to 16 mg U/m as uranium trioxide (Rothstein 1949c) and in a 5-week study of rats and mice exposed to 15 mg U/m as sodium diuranate for 6 hours per day, 5V2 days per week (Rothstein 1949d). 

Heid KR, Fuqua PA. 1974. Review of uranium inhalation case. Health Phys 26 399-403. 

Care must be taken in handling radon, as with other radioactive materials. The main hazard is from inhalation of the element and its solid daughters which are collected on dust in the air. Good ventilation should be provided where radium, thorium, or actinium is stored to prevent build-up of the element. Radon build-up is a health consideration in uranium mines. Recently radon build-up in homes has been a concern. Many deaths from lung cancer are caused by radon exposure. In the U.S. it is recommended that remedial action be taken if the air in homes exceeds 4 pCi/1. 

Working with uranium requires the knowledge of the maximum allowable concentrations that may be inhaled or ingested. 

Handling of soluble uranium compounds requires appropriate clothing to prevent skin contact and eye protection to prevent any possible eye contact. Protective clothing requirements for insoluble uranium compounds should prevent repeated or prolonged skin contact. Eye protection for use in handling insoluble uranium compounds should prevent any possibiUty of eye contact. Respirators should always be worn to prevent inhalation of uranium dust, fumes, or gases (38). 

Uranium can enter the human body orally, by inhalation, and through the skin and mucous membranes. Uranium compounds, both soluble and insoluble, ate absorbed most readily from the lungs. In the blood of exposed animals, uranium occurs in two forms in equiUbrium with each other as a nondiffusible complex with plasma proteins and as a diffusible bicarbonate complex (242). 

Plutonium has a much shorter half-life than uranium (24.000 years for Pu-239 6,500 years for Pu-240). Plutonium is most toxic if it is inhaled. The radioactive decay that plutonium undergoes (alpha decay) is of little external consequence, since the alpha particles are blocked by human skin and travel only a few inches. If inhaled, however, the soft tissue of the lungs will suffer an internal dose of radiation. Particles may also enter the blood stream and irradiate other parts of the body. The safest way to handle plutonium is in its plutonium dioxide (PuOj) form because PuOj is virtually insoluble inside the human body, gi eatly reducing the risk of internal contamination. 

Stanley JA, Edison AF, Mewhinney JA, et al. 1978. Inhalation toxicology of industrial plutonium and uranium oxide aerosols II. Deposition, retention and dosimetry. Health Phys 35(6) 888. 

Stanley JA, Edison AF, Mewhinney JA. 1982. Distribution, retention and dosimetry of plutonium and americium in the rat, dog and monkey after inhalation of an industrial-mixed uranium and plutonium oxide aerosol. Health Phys 43(4) 521-530. 

Cross,F.T., Palmer,R.F., Filipy,R.E., Busch,R.H. and B.O. Stuart, Study on the Combined Effects of Smoking and Inhalation of Uranium Ore Dust, Radon Daughters and Diesel Oil Exhaust Fumes in Hamsters and Dogs, Pacific Northwest Laboratory Rep. No. PNL-2744> Richland, National Technical Information Service, Springfield, VA., USA (1978). 

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