The influence of dose rate, ambient temperature and time on the radiation response of Harwell PMMA dosimeters

Whittaker, B.; Watts, Michael

doi:10.1016/s0969-806x(00)00316-9

Cited by 47 publications

(24 citation statements)

References 6 publications

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“…One of the most widely used gamma dosimetry technique involves the use of dyed PMMA (poly methylmethacrylate) slides, which change colour on exposure to gamma irradiation. This radiation-induced attenuation is monitored using a spectrophotometer post-irradiation [1,2]. Different ranges can be monitored depending on the dye used, e.g., Harwell Red 4034 has a dose range of 5 kGy to 50 kGy, and Harwell [3] Gammachrome YR has a dose range of 100 Gy to 3 kGy.…”

Section: Introductionmentioning

confidence: 99%

Optical fibre sensor for the online monitoring of gamma radiation doses

O'Keeffe

Fitzpatrick

Fernandez

et al. 2007

J. Phys.: Conf. Ser.

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Abstract. The radiation-induced attenuation in poly-methylmethacrylate (PMMA) based plastic optical fibres is monitored online during exposure to gamma radiation, in an investigation in to their use as an intrinsic real-time gamma radiation dosimeter. The PMMA fibre exhibited a linear radiation-induced attenuation response at various wavelengths for a dose range of 50Gy to 50kGy. The sensitivity, ranging from 0.4 dBm -1 /kGy to 0.03 dBm -1 /kGy, is wavelength dependant, with higher sensitivity at the lower wavelengths.

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Section: Introductionmentioning

confidence: 99%

Optical fibre sensor for the online monitoring of gamma radiation doses

O'Keeffe

Fitzpatrick

Fernandez

et al. 2007

J. Phys.: Conf. Ser.

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“…Dosimeters consist of small clear rectangular pieces of polymethylmethacrylate (PMMA) that can be dyed or colourless, and are extensively used in the monitoring of irradiation of medical products (Whittaker and Watts 2001). The dyed type are normally used and of the 3 types available, red 4034 PMMA dosimeters (Harwell, Didcot, UK) are widely accepted for medical sterilisation monitoring (Whittaker and Watts 2001).…”

Section: Introductionmentioning

confidence: 99%

Validation of Radiation Dose Received by Frozen Unprocessed and Processed Bone during Terminal Sterilisation

Eagle¹,

Rooney²,

Lomas³

et al. 2005

Cell Tissue Banking

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Fresh frozen femoral heads (FH) and frozen processed bone (FP) are widely used as a source of allograft bone. The FP bone and some of the FH are terminally sterilised by the National Blood Service Tissue Services (NSBTS), via application of a minimum 25 kGy gamma radiation dose. To comply with the Guidelines for the Blood Transfusion Services in the United Kingdom (2002), frozen musculoskeletal tissue must be maintained below -40 degrees C during storage and transit. In practice, NBSTS stores bone long-term in -80 degrees C freezers. During transport for irradiation, a temperature of circa -79 degrees C is maintained by packing the bone in dry ice. An evaluation of the radiation dose received by bone has previously been made via dosimeters located within the tissue and dry ice, however, some evidence suggests that low temperature can influence the accuracy of the dosimeter readings. The aim of this study was to determine the actual radiation dose received by FH and FP bone during the irradiation process. This was accomplished by comparing radiation dose readings from dosimeters placed in dry ice with dosimeters placed in a dry ice substitute of similar dimensions and density i.e., polytetrafluoroethylene (PTFE) at ambient temperature. New packing formats were developed for both FH and FP bone such that 15 FH or 3 kg of FP bone could be irradiated in one transport box at any given time in a standardised fashion. The data show that low temperature consistently increased dosimeter readings 10--27%, and that radiation dose always fell within the range of 25--40 kGy (FH=25.1--35.7 kGy; FP bone=25.2--32.4 kGy).

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“…Absorbed doses were measured by routine dosimeters (batch X; Amber Perspex Harwell, London) with nominal uncertainty limits of about 2.5% (22). For each set of assayed conditions, one sample was irradiated per gamma radiation dose, and two independent irradiation batches were performed.…”

Section: Methodsmentioning

confidence: 99%

Tracking Human Adenovirus Inactivation by Gamma Radiation under Different Environmental Conditions

Pimenta

Guerreiro

Madureira

et al. 2016

Appl Environ Microbiol

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Adenovirus is the most prevalent enteric virus in waters worldwide due to its environmental stability, which leads to public health concerns. Mitigation strategies are therefore required. The aim of this study was to assess the inactivation of human adenovirus type 5 (HAdV-5) by gamma radiation in aqueous environments. Various substrates with different organic loads, including domestic wastewater, were inoculated with HAdV-5 either individually or in a viral pool (with murine norovirus type 1 [MNV-1]) and were irradiated in a Cobalt-60 irradiator at several gamma radiation doses (0.9 to 10.8 kGy). The infectivity of viral particles, before and after irradiation, was tested by plaque assay using A549 cells. D 10 values (dose required to inactivate 90% of a population or the dose of irradiation needed to produce a 1 log 10 reduction in the population) were estimated for each substrate based on virus infectivity inactivation exponential kinetics. The capability of two detection methods, nested PCR and enzyme-linked immunosorbent assay (ELISA), to track inactivated viral particles was also assessed. After irradiation at 3.5 kGy, a reduction of the HAdV-5 titer of 4 log PFU/ml on substrates with lower organic loads was obtained, but in highly organic matrixes, the virus titer reduction was only 1 log PFU/ml. The D 10 values of HAdV-5 in high organic substrates were significantly higher than in water suspensions. The obtained results point out some discrepancies between nested PCR, ELISA, and plaque assay on the assessments of HAdV-5 inactivation. These results suggest that the inactivation of HAdV-5 by gamma radiation, in aqueous environments, is significantly affected by substrate composition. This study highlights the virucidal potential of gamma radiation that may be used as a disinfection treatment for sustainable water supplies. IMPORTANCEHuman adenovirus (HAdV) is the most prevalent of the enteric viruses in environmental waters worldwide. The purposes of this study are to provide new insights on the inactivation of enteric virus by gamma irradiation and to introduce new concepts and reinforce the benefits and utility of radiation technologies as disinfection processes. This may be an effective tool to guarantee the reduction of viral pathogens and to contribute to public health and sustainable water supplies.

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The influence of dose rate, ambient temperature and time on the radiation response of Harwell PMMA dosimeters

Cited by 47 publications

References 6 publications

Optical fibre sensor for the online monitoring of gamma radiation doses

Optical fibre sensor for the online monitoring of gamma radiation doses

Validation of Radiation Dose Received by Frozen Unprocessed and Processed Bone during Terminal Sterilisation

Tracking Human Adenovirus Inactivation by Gamma Radiation under Different Environmental Conditions

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