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Biomedical subjects

B Kahn

Publications and source records attributed to B Kahn.

At least 37 records · Page 2Linked to original sources
PubMed1983

Search for building materials as sources of elevated radiation dose.

A systematic approach to finding materials that cause elevated gamma radiation exposure rates or 222Rn progeny working levels in buildings was tested in the Atlanta area. With the proposed procedure, exposure rates in planned structures would be derived from a radiation survey of the material performed with a NaI(T1) detector. Working level values under specified conditions would be inferred from an additional measurement of 226Ra concentration in the material. To quantify the procedure, surveyed building materials were analyzed for radionuclide content and categorized according to an exposure rate index related both to the survey meter count rate and the radionuclide concentration. An available calculational model was used to predict from the index the exposure rate in a room totally enclosed by radioactive material. An additional model was developed for application to structures where the radioactive material is only in the floor or walls. 222Radon concentrations in an enclosed space were also predicted according to an available model. Exposure rates were measured in newly constructed buildings to test the approach. Measurements in older buildings found elevated gamma-ray emission from concrete blocks made with phosphate slag from a phosphorus producer in Alabama. Buildings with walls of these blocks were used to test the prediction of 222Rn concentrations in building air due to 226Ra in construction material. The calculational models predicted that the 226Ra concentration of approx. 20 pCi/g in these blocks would result in increases of the average exposure rates by 10 mu R/hr and of 222Rn concentrations by 0.2 pCi/l. under specified conditions. Observed levels were consistent with these predictions, but the major fraction of 222Rn in room air was attributed to inflow from the ground beneath the building.

Construction Materials↗
PubMed1982

Transportation of radioactive material in Georgia.

A 3-yr study of radioactive materials transportation examined the magnitude of radioactive materials shipments in terms of numbers of packages and motor vehicle trips and types of materials; compliance with regulations for packaging, labelling, handling, external radiation exposure, and surface contamination; and dose to workers as measured with personnel dosimeters. Much of the information was obtained at the Atlanta airport and its vicinity, a package distribution center for the southeastern U.S., and at the Barnwell, S.C. radioactive waste burial site, the destination of most shipments of radioactive waste from or through Georgia. Approximately 12,000 packages in radioactive material categories I, II and III were handled in Georgia each year. Motor vehicles made approximately 3300 trips per year. Some instances of noncompliance were observed, but few of them had the potential for elevated radiation exposure of persons. Several incidents associated with radioactive material transport are reported, of which one may have resulted in slightly elevated exposures to persons. Among drivers and handlers who worked with radioactive material shipments, dosimeters showed that less than one-half of them received radiation doses above background levels. The highest doses were found for drivers who transported large numbers of 99Mo generators.

Georgia↗
PubMed1982

Monitoring the critical radiation exposure pathways at a BWR nuclear power station.

Iodine-131 in milk and gamma radiation from radionuclides in air in the environment of a 3-unit nuclear power station were measured at the levels predicted for airborne effluent. These measurements were part of a modified environmental radiological monitoring program to confirm the population doses computed from radionuclide release rates and environmental transfer models. The limits of detection were lowered relative to conventional monitoring programs by analyzing 21 L samples of milk for 131I and by determining external gamma radiation with a system that combined use of thermoluminescent dosimeters, pressurized ionization chambers, and NaI(T1) survey meters. For monitoring periods slightly longer than 6 months, during a time when fallout from atmospheric nuclear tests contributed very little, the average measured 131I concentration in milk was 0.1 pCi/L for cows on a nearby pasture and 0.02 pCi/L for cows at a more distant control location, compared to predicted values of 0.07 and 0.02 pCi/L, respectively; the average radiation exposure from airborne radionuclides measured at 16 nearby dosimeter locations was 7 mR, compared to the average of predicted values of 4 mR.

Animals↗
PubMed1979

Superior gluteal artery laceration, a complication of iliac bone graft surgery.

In the 2 cases cited, laceration of the superior gluteal artery occurred when removing bone from the posterior ilium. A review of the anatomy shows how the superior gluteal artery, as it exists the sciatic notch, can be compressed locally and exposed for clipping or ligation. The internal iliac artery can be occluded by embolization of a Fogerty catheter. The bony origin of the gluteus maximus is a good landmark to help avoid entering the sciatic notch and a special retractor provides the necessary exposure.

Adult↗
PubMed1978

Foreign body (palm thorn) in knee joint.

A child who lives in a semitropical or tropical zone and has monarticular symptoms involving the knee joint and a history of playing in the vicinity of plams should be examined for the possibility of a palm thorn within the joint. The diagnosis, made after careful elimination of more common entities, can only be confirmed by surgical exploration.

California↗