Design and performance of a recirculating radon-progeny aerosol generation and animal inhalation exposure system
- Inhalation Toxicology Research Institute, Albuquerque, NM (United States)
At Inhalation Toxicology Research Institute we are conducting inhalation studies that expose laboratory animals to {sup 222}Rn progeny attached to vector aerosols typical of indoor and mine environments. These studies require exposures of up to 1500 working level months within a few hours. Thus, large amounts of {sup 226}Ra are needed to produce the gaseous {sup 222}Rn. A once-through exposure system was considered impractical because of statutory discharge limitations for radon and the large amounts of radium required. We therefore designed and constructed a recirculating exposure system that removes the aerosol after it has passed through the exposure chambers and recirculates the remaining purified radon. The purified radon and air mixture is then passed into a reaction aging chamber, where ingrowth of the progeny and their attachment to vector aerosols occur. The design includes (1) allowance for 45 mg {sup 226}Ra in the radon generator, (2) 40 L min{sup {minus}1} total flow rate, (3) CO{sub 2} removal, (4) reconstitution of oxygen tension and water vapor content to ambient levels, and (5) a trap for radon gas. Radon progeny exposure concentrations in the range of 5,000 to 100,000 working levels have been produced.
- OSTI ID:
- 44906
- Report Number(s):
- CONF-901010-Pt.2; TRN: 95:003335-0011
- Resource Relation:
- Conference: 29. Hanford symposium on health and the environment: indoor radon and lung cancer--reality or myth, Richland, WA (United States), 15-19 Oct 1990; Other Information: PBD: 1992; Related Information: Is Part Of Indoor radon and lung cancer: Reality or myth? Part 2; Cross, F.T. [ed.]; PB: 599 p.
- Country of Publication:
- United States
- Language:
- English
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