{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,5]],"date-time":"2026-01-05T15:10:10Z","timestamp":1767625810768,"version":"3.40.2"},"reference-count":49,"publisher":"Oxford University Press (OUP)","issue":"4","license":[{"start":{"date-parts":[[2025,3,10]],"date-time":"2025-03-10T00:00:00Z","timestamp":1741564800000},"content-version":"vor","delay-in-days":9,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Atomic Energy of Canada Limited\u2019s Federal Nuclear Science & Technology Work Plan"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,3,21]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>The reported relative biological effectiveness (RBE) for thermal neutrons has a large range (5\u201351, for cytogenetic endpoints), which can confound radiation protection decision-making. To determine whether thermal neutron spectra can influence RBE, the RBE of reactor-derived thermal neutrons of average energy 31\u00a0meV was evaluated in human peripheral blood lymphocytes using two classical DNA double-strand break endpoints: the dicentric chromosome assay (DCA) and the cytokinesis-block micronucleus assay. Dose-response curves for 41 to 408\u00a0mGy revealed a preference for linear regression. Maximum RBE (RBEM) values of 6.7\u00a0\u00b1\u00a00.9 and 4.4\u00a0\u00b1\u00a00.7 were calculated for the DCA and the micronucleus assay, respectively. These 31\u00a0meV RBEM values were significantly lower than our prior results for 64\u00a0meV thermal neutrons, which yielded a DCA RBEM of 11.3\u00a0\u00b1\u00a01.6 and a micronucleus RBEM of 9.0\u00a0\u00b1\u00a01.1. Dose-specific RBE values decreased with increasing dose for both assays. Microdosimetry simulations demonstrated similar quality factor values for both thermal neutron spectra. Dose deposition differences on the cellular scale, the difference in dose rate between irradiation configurations, or a not-yet understood phenomenon may be responsible for the RBE difference between the 31 and 64\u00a0meV thermal spectra. These findings indicate that the currently accepted radiation weighting factor wR value of 2.5 for thermal neutrons may underestimate the radiation detriment to small or shallow tissue targets including the lens of the eye.<\/jats:p>","DOI":"10.1093\/rpd\/ncae231","type":"journal-article","created":{"date-parts":[[2025,3,10]],"date-time":"2025-03-10T13:37:56Z","timestamp":1741613876000},"page":"297-313","source":"Crossref","is-referenced-by-count":2,"title":["Relative biological effectiveness of 31\u00a0meV thermal neutrons in peripheral blood lymphocytes"],"prefix":"10.1093","volume":"201","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-5649-9432","authenticated-orcid":false,"given":"Laura C","family":"Paterson","sequence":"first","affiliation":[{"name":"Radiobiology and Health Branch , , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]},{"name":"Canadian Nuclear Laboratories , , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]},{"name":"Medical Physics Unit, McGill University , Montreal, QC H4A 3J1 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fawaz","family":"Ali","sequence":"additional","affiliation":[{"name":"Biology R&D Facility Branch, Canadian Nuclear Laboratories , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mohsen","family":"Naseri","sequence":"additional","affiliation":[{"name":"Applied Physics Branch, Canadian Nuclear Laboratories , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"David","family":"Perez Loureiro","sequence":"additional","affiliation":[{"name":"Applied Physics Branch, Canadian Nuclear Laboratories , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amy","family":"Festarini","sequence":"additional","affiliation":[{"name":"Environment and Waste Technologies Branch, Canadian Nuclear Laboratories , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marilyne","family":"Stuart","sequence":"additional","affiliation":[{"name":"Environment and Waste Technologies Branch, Canadian Nuclear Laboratories , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chad","family":"Boyer","sequence":"additional","affiliation":[{"name":"Advanced Fuels and Reactor Physics Branch, Canadian Nuclear Laboratories , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ronald","family":"Rogge","sequence":"additional","affiliation":[{"name":"National Security and Critical Infrastructure Directorate, Canadian Nuclear Laboratories , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christie","family":"Costello","sequence":"additional","affiliation":[{"name":"Radiobiology and Health Branch , , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]},{"name":"Canadian Nuclear Laboratories , , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Norma","family":"Ybarra","sequence":"additional","affiliation":[{"name":"Medical Physics Unit, McGill University , Montreal, QC H4A 3J1 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7084-1425","authenticated-orcid":false,"given":"John","family":"Kildea","sequence":"additional","affiliation":[{"name":"Medical Physics Unit, McGill University , Montreal, QC H4A 3J1 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8058-4162","authenticated-orcid":false,"given":"Richard B","family":"Richardson","sequence":"additional","affiliation":[{"name":"Radiobiology and Health Branch , , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]},{"name":"Canadian Nuclear Laboratories , , 286 Plant Rd, Chalk River, ON K0J 1J0 ,","place":["Canada"]},{"name":"Medical Physics Unit, McGill University , Montreal, QC H4A 3J1 ,","place":["Canada"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[2025,3,10]]},"reference":[{"key":"2025032118442274200_ref1","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/S0146-6453(03)00024-1","volume-title":"quality factor (Q), and radiation weighting factor (wR)","author":"International Commission on Radiation Protection. 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