Isabel M. Fisenne

The daily intake of 234,235,238U, 228,230,232Th and 226,228Ra by New York City residents

The daily intake of long-lived alpha-emitting members of the U, Th and Ac series by New York City residents has been estimated from measurements of diet, water and air samples. The total daily intakes from inhalation, food and water consumption in mBq are 18 (234U), 0.7 (235U), 16 (238U), 6 (230Th), 4 (232Th) and 52 (226Ra). From this, we infer that the total daily intakes of 228Th and 228Ra are 4 and 35 mBq, respectively.

Natural U concentrations in soft tissues and bone of New York City residents

Specimens of lung, liver, kidney and vertebrae from New York City autopsy cases were measured for naturally occurring U. An age dependency in U concentration was found in lung and vertebrae. The bone concentration was found to be a factor of 10 lower than previously reported for this tissue, thus the skeletal burden of U is estimated to be factor of 10 lower than that suggested in ICRP Publication 23.

Measured intake and excretion patterns of naturally occurring 234U, 238U, and calcium in humans.

The normal dietary and fluid intake and urinary and fecal excretion of 234U and 238U were determined in humans under strictly controlled conditions in the Metabolic Research Ward at Hines Hospital. These values formed the basis of the metabolic balances of these uranium isotopes. The major pathway of 234U and of 238U excretion was via the intestine while the urinary 234U and 238U were very low, averaging 2% of the total excretion. The uranium balances were roughly in equilibrium. These data were used in combination with measurements of tissue concentrations of uranium from nonoccupationally exposed humans to calculate steady-state uptake factors for environmental exposure to uranium isotopes during baseline conditions of a normal dietary intake.

Fallout plutonium in human tissues from New York City

Fallout /sup 239/ /sup 240/Pu concentrations were measured in lung, liver, kidney, vertebrae, and lymph nodes obtained at autopsy during 1973 to 1974 from New York City residents. For the study population, the fallout plutonium tissue concentrations in descending order were liver > bone > lymph node > lung > kidney with median concentrations of 0.37, 0.25, 0.11, 0.06, and 0.05 pCi/kg, respectively.

Measured 234,238U and Fallout 239,240Pu in Human Bone Ash from Nepal and Australia: Skeletal Alpha Dose

Human bone samples from Nepal and Australia were analyzed for isotopic uranium and fallout plutonium. The Nepalese samples were obtained for a 3-yr period (1976-78) while the Australian samples are representative of a single year (1977). The surface air plutonium concentrations for the latitude bands of these countries were either measured and/or estimated from 1954 through 1978. With the plutonium air concentrations and age-dependent breathing rates as input data, the measured human bone results were compared with skeletal estimates derived from the ICRP Task Group Inhalation Model, and the agreement was found to be reasonably good. The measured isotopic uranium concentrations in these samples provide a benchmark against which to assess fallout plutonium based upon a comparison of the skeletal alpha radiation dose from a natural actinide to these populations.

Worldwide measurement of 226Ra in human bone: estimate of skeletal alpha dose.

AbstractMeasurement of 226Ra and calcium in 588 samples of human vertebrae from 13 countries are combined with those of other investigators to describe the average global 226Ra concentration in human bone. The median population-weighted concentration is 23 fCi 226Ra/g of calcium. The median concentr

210Pb in Indoor Air by Total Alpha Measurement

210Pb has been measured in indoor air by two methods. Low flow rate pumps and membrane filters were used to collect the samples. The air filter samples were stored for 1.7 y, after which total alpha activity was determined by scintillation counting. 210Pb was then chemically separated and measured by alpha spectrometry. The efficacy of determination of 210Pb by total alpha measurement was empirically proven. The average air concentration determined by total alpha counting was 340 microBq 210Pb m-3 and 360 microBq 210Pb m-3 by radiochemical analysis.

Initial study of 210Pb in indoor air.

An exploratory program was undertaken to determine the feasibility of measuring the indoor air concentration of 210Pb. Low flow rate pumps and membrane filters were used to collect samples in an office. The air filter samples were stored for 1.6 y and 210Po was chemically separated and measured by alpha spectrometry. Unsupported 210Po was also determined in air samples collected at a later time. The average air concentrations were 150 microBq 210 Pb m-3 and 12 microBq 210Po m-3. The average indoor to outdoor ratio of 210Pb in air is estimated to be 0.25.

Radon water to air transfer measured in a bathroom in an energy-efficient home with a private well

Monthly measurements of radon in kitchen and bath tap water along with indoor air concentrations were made from 1994 to 1996 in an energy-efficient home with a private well. The well supplies all water to the home. The radon in cold and hot kitchen water averaged 69±2 and 52±2 Bq l(-1), respectively. Radon in cold and hot water from the bath/shower room shower head averaged 60±1 and 38±2 Bq l(-1), respectively, whereas hot water collected in the shower at the tub base averaged 5±1 Bq l(-1) or a 92% radon loss to air. While the calculated transfer factor of 1/10,000, i.e. radon concentration in air to radon in water, conventionally applies to the whole house, measurements for the specific water release during showering in a bathroom exhibit a larger transfer factor of 1/2300, due to smaller room volume.

SEISMIC PREDICTION USING UNATTACHED RADON DECAY PRODUCTS

Long-term measurements of the 222Rn concentration, 222Rn decay product activity, particle size distribution, and unattached, and attached 222Rn decay products, were made at two locations using the 22 y radon decay product 210Pb as their tracer. The particle size sampler collects both short lived 222Rn decay products that ultimately decay to 210Pb on the filters, and also airborne 210Pb. The measurements were made outdoors, at a suburban home and at Fernald, OH, a former uranium processing facility, on top of one of the two 226Ra storage silos containing 150 TBq 226Ra. The size distributions showed the unattached fractions, i.e. particle diameter 2-4 nm, to be 1.5% at the home and 14% at the silos. The unattached fraction of 218Po can be shown to be an immediate measure of the 222Rn concentration. The data indicates detection of the pressure driven 222Rn flow at the silo and with the enhanced measurement capability of a filtered air source versus the usual 222Rn gas measurement. It is proposed that real time measurements of unattached 218Po may be used to identify rapidly changing 222Rn concentrations associated with pressure driven soil air flow associated with seismic activity.