Abstract
In looking for any contribution of recoil or transmutation processes with internally deposited radioactive isotopes by comparison with the biological effects following gamma radiation exposure to produce the same absorbed dose, the various factors affecting local energy deposition must be carefully considered. For the same activity per unit volume of culture medium a higher specific activity results in increased nuclear incorporation and resultant cell lethality. Also for materials localized in the nucleus only (e.g. thymidine) the dimensions of the deposit may limit the nuclear dose, so that although {sup 14}C disintegrations release some ten times more energy than {sup 3}H, the biological effects demonstrated for the same nuclear activity (in {mu}Ci) are similar. Although the ICRP Recommendations give a QF of 1.7 for {sup 3}H beta particles, published results vary from 1.0 to about 2.0. Recent experiments using both mammalian cells in culture and bean roots have shown clearly that the RBE varies with dose rate, from unity for dose rates of 1 rad/min or above to 1.7 for dose rates of about 1 rad/h, a conclusion which is in fact in agreement with other published results. In this connection the local energy distribution is considered theoretically for {sup 3}H
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Oliver, R.
[1]
- Department of Radiation Physics, Churchill Hospital, Oxford (United Kingdom)
Citation Formats
Oliver, R.
Some Dosimetric and Radiation Protection Aspects of Cellular Irradiation from Incorporated Radioactive Materials.
IAEA: N. p.,
1968.
Web.
Oliver, R.
Some Dosimetric and Radiation Protection Aspects of Cellular Irradiation from Incorporated Radioactive Materials.
IAEA.
Oliver, R.
1968.
"Some Dosimetric and Radiation Protection Aspects of Cellular Irradiation from Incorporated Radioactive Materials."
IAEA.
@misc{etde_22190164,
title = {Some Dosimetric and Radiation Protection Aspects of Cellular Irradiation from Incorporated Radioactive Materials}
author = {Oliver, R.}
abstractNote = {In looking for any contribution of recoil or transmutation processes with internally deposited radioactive isotopes by comparison with the biological effects following gamma radiation exposure to produce the same absorbed dose, the various factors affecting local energy deposition must be carefully considered. For the same activity per unit volume of culture medium a higher specific activity results in increased nuclear incorporation and resultant cell lethality. Also for materials localized in the nucleus only (e.g. thymidine) the dimensions of the deposit may limit the nuclear dose, so that although {sup 14}C disintegrations release some ten times more energy than {sup 3}H, the biological effects demonstrated for the same nuclear activity (in {mu}Ci) are similar. Although the ICRP Recommendations give a QF of 1.7 for {sup 3}H beta particles, published results vary from 1.0 to about 2.0. Recent experiments using both mammalian cells in culture and bean roots have shown clearly that the RBE varies with dose rate, from unity for dose rates of 1 rad/min or above to 1.7 for dose rates of about 1 rad/h, a conclusion which is in fact in agreement with other published results. In this connection the local energy distribution is considered theoretically for {sup 3}H disintegrations and for gamma radiation, using in the latter case the data published by Rossi. If for a similar nuclear dose H beta particles have an RBE of unity relative to gamma radiation, it appears that there is no significant extra contribution to damage from recoil or transmutation processes. As {sup 14}C appears to be no more damaging than SH under similar conditions the same conclusion also applies for this nuclide. (author)}
place = {IAEA}
year = {1968}
month = {Jun}
}
title = {Some Dosimetric and Radiation Protection Aspects of Cellular Irradiation from Incorporated Radioactive Materials}
author = {Oliver, R.}
abstractNote = {In looking for any contribution of recoil or transmutation processes with internally deposited radioactive isotopes by comparison with the biological effects following gamma radiation exposure to produce the same absorbed dose, the various factors affecting local energy deposition must be carefully considered. For the same activity per unit volume of culture medium a higher specific activity results in increased nuclear incorporation and resultant cell lethality. Also for materials localized in the nucleus only (e.g. thymidine) the dimensions of the deposit may limit the nuclear dose, so that although {sup 14}C disintegrations release some ten times more energy than {sup 3}H, the biological effects demonstrated for the same nuclear activity (in {mu}Ci) are similar. Although the ICRP Recommendations give a QF of 1.7 for {sup 3}H beta particles, published results vary from 1.0 to about 2.0. Recent experiments using both mammalian cells in culture and bean roots have shown clearly that the RBE varies with dose rate, from unity for dose rates of 1 rad/min or above to 1.7 for dose rates of about 1 rad/h, a conclusion which is in fact in agreement with other published results. In this connection the local energy distribution is considered theoretically for {sup 3}H disintegrations and for gamma radiation, using in the latter case the data published by Rossi. If for a similar nuclear dose H beta particles have an RBE of unity relative to gamma radiation, it appears that there is no significant extra contribution to damage from recoil or transmutation processes. As {sup 14}C appears to be no more damaging than SH under similar conditions the same conclusion also applies for this nuclide. (author)}
place = {IAEA}
year = {1968}
month = {Jun}
}