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Calabrese E, Giordano J, Selby PB. Recent discoveries on the historical foundations of cancer risk assessment: Shedding light on the limits of LNT. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 941:173676. [PMID: 38823696 DOI: 10.1016/j.scitotenv.2024.173676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 05/29/2024] [Accepted: 05/29/2024] [Indexed: 06/03/2024]
Abstract
Within the past three years there has been a spate of historical discoveries by our research team on various different facets of the historical foundations of cancer risk assessment. This series of discoveries was stimulated by the creation of a 22-episode documentary of the historical foundations of cancer risk assessment by the US Health Physics Society and the need to provide documentation. This process yielded nearly two dozen distinct historical findings which have been published in numerous papers in the peer-reviewed literature. These discoveries are itemized and summarized in the present paper, along with the significance of each discovery within the historical context of ionizing radiation research and cancer risk assessment.
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Affiliation(s)
- Edward Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003, USA.
| | - James Giordano
- Departments of Neurology and Biochemistry; Pellegrino Center for Clinical Bioethics; Georgetown University Medical Center, Washington, DC 20007, USA.
| | - Paul B Selby
- Retired from: Oak Ridge National Laboratory, Oak Ridge, TN, USA; 4088 Nottinghill Gate Road, Upper Arlington, OH 43220, USA
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Calabrese EJ, Selby PB. Newly discovered letter: why Muller failed to cite the negative mouse mutation findings of Snell, preserving his chances to receive the Nobel Prize. Arch Toxicol 2024; 98:2739-2741. [PMID: 38909170 DOI: 10.1007/s00204-024-03807-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 06/24/2024]
Abstract
A recently acquired letter between Hermann Muller and his wife (March 21, 1933) reveals that Muller had learned that he had been nominated for the Nobel Prize in 1932 with about 1/3 of the total votes being supportive. Muller was hopeful that over time sufficient votes would lead to receiving the award. The knowledge of Muller on this matter and its timing provide a likely explanation why Muller never cited the negative mouse mutation findings of George Snell, performed under Muller's direction during that time period. This action of Muller, along with the failure of Snell to promote his discovery, greatly reduced the chances that those findings would complicate his attempt to garner support for his LNT single-hit model and its application to hereditary and cancer risk assessment. It also helped Muller achieve the Nobel Prize, allowing him the necessary international visibility to promote his ideologically driven ionizing radiation-related LNT-based paradigm.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory, TN; 4088 Nottinghill Gate Road, Upper Arlington, OH, 43220, USA
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Calabrese E, Selby PB. First report of X-ray induced somatic mutation by Muller's department chair fails to support Muller's linearity hypothesis. Arch Toxicol 2024; 98:2731-2737. [PMID: 38909339 DOI: 10.1007/s00204-024-03808-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 06/24/2024]
Abstract
This paper reevaluates the first report of X-ray-induced somatic gene mutations. It was undertaken by John Patterson, Department Chair of Hermann Muller, using the same biological model, methods and equipment of Muller. Patterson reported X-ray induced mutation frequencies for X-chromosome-linked (sex-linked) recessive gene mutations in somatic cells of Drosophila melanogaster that resulted in color changes in the ommatidia of the eyes. Results were based on color changes detected in both male and female offspring irradiated while in egg, larval or pupal stages and for unirradiated controls. Patterson claimed that the observed dose response displayed linearity, with a clear implication that the linear response extended to background exposure levels of unirradiated controls. This reanalysis disputes Patterson's interpretation, showing that the dose response in the low-dose zone strongly supported a threshold model. The doses in the experiment, which were not clearly presented, were so high that it would preclude the assumption that the experiment provided any information of relevance to radiation exposures of humans at low doses, or even at high doses delivered at low-dose rates. Induced phenotypical changes that occurred at the higher doses, especially in female offspring, overwhelmingly resulted from X-ray-induced chromosome breaks instead of point mutations as initially expected by Patterson. The Patterson findings and linearity interpretations were an important contributory factor in the acceptance of the linear non-threshold (LNT) model during the formative time of concept consolidation. It is rather shocking now to see that the actual data provided no support for the LNT model.
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Affiliation(s)
- Edward Calabrese
- Department of Environmental Health Sciences, University of Massachusetts, Morrill I, N344, Amherst, MA, 01003, USA.
| | - Paul B Selby
- Retired From Oak Ridge National Laboratory at Oak Ridge, TN, 4088 Nottinghill Gate Road, Upper Arlington, OH, 43220, USA
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Calabrese EJ, Selby PB. Muller and mutations: mouse study of George Snell (a postdoc of Muller) fails to confirm Muller's fruit fly findings, and Muller fails to cite Snell's findings. Arch Toxicol 2024; 98:1953-1963. [PMID: 38573337 DOI: 10.1007/s00204-024-03718-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 04/05/2024]
Abstract
In 1931, Hermann J. Muller's postdoctoral student, George D. Snell (Nobel Prize recipient--1980) initiated research to replicate with mice Muller's X-ray-induced mutational findings with fruit flies. Snell failed to induce the two types of mutations of interest, based on fly data (sex-linked lethals/recessive visible mutations) even though the study was well designed, used large doses of X-rays, and was published in Genetics. These findings were never cited by Muller, and the Snell paper (Snell, Genetics 20:545-567, 1935) did not cite the 1927 Muller paper (Muller, Science 66:84, 1927). This situation raises questions concerning how Snell wrote the paper (e.g., ignoring the significance of not providing support for Muller's findings in a mammal). The question may be raised whether professional pressures were placed upon Snell to downplay the significance of his findings, which could have negatively impacted the career of Muller and the LNT theory. While Muller would receive worldwide attention, and receive the Nobel Prize in 1946 "for the discovery that mutations can be induced by X-rays," Snell's negative mutation data were almost entirely ignored by his contemporary and subsequent radiation genetics/mutation researchers. This raises questions concerning how the apparent lack of interest in Snell's negative findings helped Muller professionally, including his success in using his fruit fly data to influence hereditary and cancer risk assessment and to obtain the Nobel Prize.
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Affiliation(s)
- Edward J Calabrese
- Toxicology, School of Public Health and Health Sciences, Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory at Oak Ridge, TN, 4088 Notting Hill Gate Road, Upper Arlington, OH, 43220, USA
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Mothersill C, Seymour C, Cocchetto A, Williams D. Factors Influencing Effects of Low-dose Radiation Exposure. HEALTH PHYSICS 2024; 126:296-308. [PMID: 38526248 DOI: 10.1097/hp.0000000000001816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
ABSTRACT It is now well accepted that the mechanisms induced by low-dose exposures to ionizing radiation (LDR) are different from those occurring after high-dose exposures. However, the downstream effects of these mechanisms are unclear as are the quantitative relationships between exposure, effect, harm, and risk. In this paper, we will discuss the mechanisms known to be important with an overall emphasis on how so-called "non-targeted effects" (NTE) communicate and coordinate responses to LDR. Targeted deposition of ionizing radiation energy in cells causing DNA damage is still regarded as the dominant trigger leading to all downstream events whether targeted or non-targeted. We regard this as an over-simplification dating back to formal target theory. It ignores that last 100 y of biological research into stress responses and signaling mechanisms in organisms exposed to toxic substances, including ionizing radiation. We will provide evidence for situations where energy deposition in cellular targets alone cannot be plausible as a mechanism for LDR effects. An example is where the energy deposition takes place in an organism not receiving the radiation dose. We will also discuss how effects after LDR depend more on dose rate and radiation quality rather than actual dose, which appears rather irrelevant. Finally, we will use recent evidence from studies of cataract and melanoma induction to suggest that after LDR, post-translational effects, such as protein misfolding or defects in energy metabolism or mitochondrial function, may dominate the etiology and progression of the disease. A focus on such novel pathways may open the way to successful prophylaxis and development of new biomarkers for better risk assessment after low dose exposures.
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Affiliation(s)
- Carmel Mothersill
- Department of Biology, McMaster University, 1280 Main St., Hamilton, ON, Canada L8S 4L8
| | - Colin Seymour
- Department of Biology, McMaster University, 1280 Main St., Hamilton, ON, Canada L8S 4L8
| | - Alan Cocchetto
- The National CFIDS Foundation, 285 Beach Ave., Hull, MA 02045
| | - David Williams
- Cambridge University, The Old Schools, Trinity Lane, Cambridge CB2 1TN, United Kingdom
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Boretti A. Selectively addressing total risk avoidance for certain chemicals while overlooking others: The case of per-and-poly-fluoroalkyls. Regul Toxicol Pharmacol 2024; 149:105602. [PMID: 38499056 DOI: 10.1016/j.yrtph.2024.105602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/04/2024] [Accepted: 03/12/2024] [Indexed: 03/20/2024]
Affiliation(s)
- Alberto Boretti
- Melbourne Institute of Technology, 288 Latrobe Street, Melbourne, 3000, VIC, Australia.
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Chaurasia RK, Sapra BK, Aswal DK. Interplay of immune modulation, adaptive response and hormesis: Suggestive of threshold for clinical manifestation of effects of ionizing radiation at low doses? THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170178. [PMID: 38280586 DOI: 10.1016/j.scitotenv.2024.170178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 12/26/2023] [Accepted: 01/13/2024] [Indexed: 01/29/2024]
Abstract
The health impacts of low-dose ionizing radiation exposures have been a subject of debate over the last three to four decades. While there has been enough evidence of "no adverse observable" health effects at low doses and low dose rates, the hypothesis of "Linear No Threshold" continues to rule and govern the principles of radiation protection and the formulation of regulations and public policies. In adopting this conservative approach, the role of the biological processes underway in the human body is kept at abeyance. This review consolidates the available studies that discuss all related biological pathways and repair mechanisms that inhibit the progression of deleterious effects at low doses and low dose rates of ionizing radiation. It is pertinent that, taking cognizance of these processes, there is a need to have a relook at policies of radiation protection, which as of now are too stringent, leading to undue economic losses and negative public perception about radiation.
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Affiliation(s)
- R K Chaurasia
- Radiological Physics and Advisory Division, India; Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
| | - B K Sapra
- Radiological Physics and Advisory Division, India; Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
| | - D K Aswal
- Health, Safety and Environment Group,Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Mumbai 400094, India.
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Calabrese EJ, Giordano J. How Hermann J. Muller Viewed the Ernest Sternglass Contributions to Hereditary and Cancer Risk Assessment. HEALTH PHYSICS 2024; 126:151-155. [PMID: 38252948 DOI: 10.1097/hp.0000000000001774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
ABSTRACT As one of the most influential radiation geneticists of the 20th century, Hermann J. Muller had a major role in the development and widespread acceptance of the linear no-threshold (LNT) dose response for hereditary and cancer risk assessments worldwide. However, a spate of historical reassessments have challenged the fundamental scientific foundations of the LNT model, drawing considerable attention to issues of ethical probity and the scientific leadership of Muller. This review paper raises further questions about the objectivity of Muller with respect to the LNT model. It is shown that Muller supported Ernest Sternglass's findings and interpretations concerning radiation-induced childhood leukemia, which have been widely and consistently discredited. These findings provide further evidence that Muller's actions with respect to radiation cancer risk assessment were far more ideologically than scientifically based.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003
| | - James Giordano
- Departments of Neurology and Biochemistry, Pellegrino Center for Clinical Bioethics, Georgetown University Medical Center, Washington, DC 20007
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Calabrese EJ. Cancer risk assessment, its wretched history and what it means for public health. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2024; 21:220-238. [PMID: 38452003 DOI: 10.1080/15459624.2024.2311300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, Massachusetts
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Paustenbach DJ, Brown SE, Heywood JJ, Donnell MT, Eaton DL. Risk characterization of N-nitrosodimethylamine in pharmaceuticals. Food Chem Toxicol 2024; 186:114498. [PMID: 38341171 DOI: 10.1016/j.fct.2024.114498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/23/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024]
Abstract
Since 2018, N-nitrosodimethylamine (NDMA) has been a reported contaminant in numerous pharmaceutical products. To guide the pharmaceutical industry, FDA identified an acceptable intake (AI) of 96 ng/day NDMA. The approach assumed a linear extrapolation from the Carcinogenic Potency Database (CPDB) harmonic-mean TD50 identified in chronic studies in rats. Although NDMA has been thought to act as a mutagenic carcinogen in experimental animals, it has not been classified as a known human carcinogen by any regulatory agency. Humans are exposed to high daily exogenous and endogenous doses of NDMA. Due to the likelihood of a threshold dose for NDMA-related tumors in animals, we believe that there is ample scientific basis to utilize the threshold-based benchmark dose or point-of-departure (POD) approach when estimating a Permissible Daily Exposure limit (PDE) for NDMA. We estimated that 29,000 ng/kg/day was an appropriate POD for calculating a PDE. Assuming an average bodyweight of 50 kg, we expect that human exposures to NDMA at doses below 5800 ng/day in pharmaceuticals would not result in an increased risk of liver cancer, and that there is little, if any, risk for any other type of cancer, when accounting for the mode-of-action in humans.
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Affiliation(s)
- D J Paustenbach
- Paustenbach and Associates, 970 West Broadway, Suite E, Jackson, WY, USA
| | - S E Brown
- Paustenbach and Associates, 207 Canyon Blvd, Boulder, CO, USA.
| | - J J Heywood
- Paustenbach and Associates, 207 Canyon Blvd, Boulder, CO, USA
| | - M T Donnell
- Valeo Sciences LLC, 333 Corporate Drive, Suite 130, Ladera Ranch, CA, USA
| | - D L Eaton
- Professor Emeritus, Department of Environmental & Occupational Health Sciences, University of Washington, Seattle, WA, USA
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Calabrese EJ, Selby PB. Muller misled the Pugwash Conference on radiation risks. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2024; 21:136-143. [PMID: 37812193 DOI: 10.1080/15459624.2023.2268664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The Pugwash Conferences have been a highly visible attempt to create profoundly important discussions on matters related to global safety and security at the highest levels, starting in 1957 at the height of the Cold War. This paper assesses, for the first time, the formal comments offered at this first Pugwash Conference by the Nobel Prize-winning radiation geneticist, Hermann J. Muller, on the effects of ionizing radiation on the human genome. This analysis shows that the presentation by Muller was highly biased and contained scientific errors and misrepresentations of the scientific record that resulted in seriously misleading the attendees. The presentation of Muller at Pugwash served to promote, on a very visible global scale, continued misrepresentations of the state of the science and had a significant impact on policies and practices internationally and both scientific and personal belief systems concerning the effects of low dose radiation on human health. These misrepresentations would come to affect the adoption and use of nuclear technologies and the science of radiological and chemical carcinogen health risk assessment, ultimately having a profound effect on global environmental health.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Paul B Selby
- Oak Ridge National Laboratory, Oak Ridge, Tennessee
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Calabrese EJ, Selby PB. Muller's genetic load/species extinction hypothesis. ENVIRONMENTAL RESEARCH 2024; 241:117599. [PMID: 37952856 DOI: 10.1016/j.envres.2023.117599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/14/2023]
Abstract
The genetic load hypothesis of Hermann Muller raised the profound question of possible species extinction, even for humans, following a prolonged accumulation of recessive genes due to ionizing radiation exposure within the population. Two major mouse radiation research teams in the United States provided the most extensive tests of Muller's hypothesis. One group continued its study for more than two decades, over 82 consecutive generations, approximating 2500 human years. Even though Muller had stressed for decades his fear of species-threatening effects, no significant effects were observed for related factors such as reproductive fitness and longevity. Yet, the paper presenting the data of the 82-generation negative study has only been cited five times in 45 years. Altogether numerous laboratories worldwide collected vast amounts of data on mice, rats, and swine in an unsuccessful attempt to see if there was convincing evidence to support the genetic load theory and claims that species might deteriorate or be rendered extinct. This paper re-examines Muller's genetic load hypothesis with a new evaluation of how that hypothesis was tested and the significance of the findings, with most of those studies being completed before the BEIR I Committee Report in 1972. That committee briefly discussed the available evidence, mostly ignoring those results as they proceeded to make hereditary risk estimates both for (1) the first generation after a radiation exposure and (2) for the time, in the distant future, when a hypothetical genetic equilibrium would be reached. Their estimates assumed accumulation of harmful mutations and a linear no-threshold dose response extending all of the way down to a single ionization. More recent data on induction by ionizing radiation of dominant mutations that affect the skeletons of mice provide further robust supporting evidence that the generationally cumulative and LNT-based assumptions underpinning Muller's genetic load hypothesis are not correct.
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Affiliation(s)
- Edward J Calabrese
- School of Public Health and Health Sciences, Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory at Oak Ridge, TN; Home Address: 4088 Nottinghill Gate Road, Upper Arlington, OH, 43220, USA.
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Calabrese EJ, Selby PB. Comet assay and hormesis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 341:122929. [PMID: 37979647 DOI: 10.1016/j.envpol.2023.122929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/06/2023] [Accepted: 11/11/2023] [Indexed: 11/20/2023]
Abstract
The paper provides the first assessment of the occurrence of hormetic dose responses using the Comet assay, a genotoxic assay. Using a priori evaluative criteria based on the Hormetic Database on peer-reviewed comet assay experimental findings, numerous examples of hormetic dose responses were obtained. These responses occurred in a large and diverse range of cell types and for agents from a broad range of chemical classes. Limited attempts were made to estimate the frequency of hormesis within comet assay experimental studies using a priori entry and evaluative criteria, with results suggesting a frequency in the 40% range. These findings are important as they show that a wide range of genotoxic chemicals display evidence that is strongly suggestive of hormetic dose responses. These findings have significant implications for study design issues, including the number of doses selected, dose range and spacing. Likewise, the widespread occurrence of hormetic dose responses in this genotoxic assay has important risk assessment implications.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory at Oak Ridge, TN. Home Address: 4088 Nottinghill Gate Road, Upper Arlington, OH, 43220, USA.
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Calabrese EJ, Selby PB. Hermann Muller and his LNT scientific and policy leadership: Private communication reveals uncertainties. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166757. [PMID: 37660820 DOI: 10.1016/j.scitotenv.2023.166757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/05/2023]
Abstract
The present paper highlights numerous publications of Hermann J. Muller with a focus on his opinions concerning the validity of the linear no-threshold dose response model for hereditary and cancer risk assessment. These comments reflect a very consistent and powerfully supporting position for the LNT model. However, newly discovered correspondence between Muller and Robley D. Evans reveals that Muller was highly uncertain about the supportive science, and therefore hid his real opinions, deliberately misleading the scientific community and governmental agencies. Of further historical value is that in the correspondence with Evans, Muller proposed what might be the first articulation of an environmentally based Precautionary Principle. These perspectives have remained unknown since Muller requested Evans to keep this letter private.
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Affiliation(s)
- Edward J Calabrese
- School of Public Health and Health Sciences, Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003, United States of America.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory, Oak Ridge, TN, United States of America
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Calabrese EJ, Selby PB. Background radiation and cancer risks: A major intellectual confrontation within the domain of radiation genetics with multiple converging biological disciplines. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2023; 20:621-632. [PMID: 37642576 DOI: 10.1080/15459624.2023.2252032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
This paper assesses the judgments of leading radiation geneticists and cancer risk assessment scientists from the mid-1950s to mid-1970s that background radiation has a significant effect on human genetic disease and cancer incidence. This assumption was adopted by the National Academy of Sciences (NAS) Biological Effects of Atomic Radiation (BEAR) I Genetics Panel for genetic diseases and subsequently applied to cancer risk assessment by other leading individuals/advisory groups (e.g., International Commission on Radiation Protection-ICRP). These recommendations assumed that a sizeable proportion of human mutations originated from background radiation due to cumulative exposure over prolonged reproductive periods and the linear nature of the dose-response. This paper shows that the assumption that background radiation is a significant cause of spontaneous mutation, genetic diseases, and cancer incidence is not supported by experimental and epidemiological findings, and discredits erroneous risk assessments that improperly influenced the recommendations of national and international advisory committees, risk assessment policies, and beliefs worldwide.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, USA
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory, Oak Ridge, TN, USA
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Selby PB, Calabrese EJ. How self-interest and deception led to the adoption of the linear non-threshold dose response (LNT) model for cancer risk assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 898:165402. [PMID: 37454843 DOI: 10.1016/j.scitotenv.2023.165402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/06/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023]
Abstract
This paper clarifies scientific contributions and deceptive/self-serving decisions of William L. Russell and Liane Russell that led to the adoption of the linear non-threshold (LNT) model for cancer risk assessment by the US EPA. By deliberately failing to report an extremely large cluster of mutations in the control group of their first experiment, and thereby greatly suppressing its mutation rate, the Russells incorrectly claimed that the male mouse was 15-fold more susceptible to ionizing-radiation-induced gene mutations as compared with fruit flies. This self-serving error not only propelled their research program into one of great prominence, but it also promoted the LNT-based doubling dose (DD) concept in radiation genetics/cancer risk assessment, by the US National Academy of Sciences (NAS) Biological Effects of Atomic Radiation (BEAR) I Genetics Panel (1956). The DD concept became a central element in their recommendation that regulatory agencies switch from a threshold to an LNT model. This error occurred because of a decision by W. Russell not to report that a large cluster of control group mutations found in an experiment for which preliminary results were reported in 1951. This failure to report that cluster and similar clusters continued throughout the careers of the Russells, resulting in massive overestimation of low dose radiation risks supporting the LNT. The Russell database and the repeated claim that those data show that there is no threshold dose rate for mutation in irradiated mouse stem-cell spermatogonia, have provided mechanistic validation supporting the epidemiological LNT hypothesis for radiation-induced leukemias and cancers. This reanalysis supports the threshold model for both males and females, thereby rebutting epidemiological extrapolations from the NAS and EPA claiming support for the LNT hypothesis for cancer risk assessment. The implications of the Russell errors/deceptions, how/why they occurred, and their impact upon society are enormous and need to be addressed by scientific/regulatory agencies, affecting regulatory and litigation activities.
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Affiliation(s)
- Paul B Selby
- Retired from Oak Ridge National Laboratory at Oak Ridge, TN, Home Address: 4088 Nottinghill Gate Road, Upper Arlington, OH 43220, USA
| | - Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003, USA.
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Calabrese EJ. Confirmation that Hermann Muller was dishonest in his Nobel Prize Lecture. Arch Toxicol 2023; 97:2999-3003. [PMID: 37665363 DOI: 10.1007/s00204-023-03566-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 09/05/2023]
Abstract
In his Nobel Prize Lecture of December 12, 1946, Hermann J. Muller argued that the dose-response for ionizing radiation-induced germ cell mutations was linear and that there was ''no escape from the conclusion that there is no threshold''. However, a newly discovered commentary by the Robert L. Brent (2015) indicated that Curt Stern, after reading a draft of part of Muller's Nobel Prize Lecture, called Muller, strongly advising him to remove reference to the flawed linear non-threshold (LNT)-supportive Ray-Chaudhuri findings and strongly encouraged him to be guided by the threshold supportive data of Ernst Caspari. Brent indicated that Stern recounted this experience during a genetics class at the University of Rochester. Brent wrote that Muller refused to follow Stern's advice, thereby proclaiming support for the LNT dose-response while withholding evidence that was contrary during his Nobel Prize Lecture. This finding is of historical importance since Muller's Nobel Prize Lecture gained considerable international attention and was a turning point in the acceptance of the linearity model for radiation and chemical hereditary and carcinogen risk assessment.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
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Calabrese EJ, Selby PB. Muller mistakes: The linear no-threshold (LNT) dose response and US EPA's cancer risk assessment policies and practices. Chem Biol Interact 2023; 383:110653. [PMID: 37572872 DOI: 10.1016/j.cbi.2023.110653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/28/2023] [Accepted: 08/09/2023] [Indexed: 08/14/2023]
Abstract
This paper identifies the occurrence of six major conceptual scientific errors of Hermann Muller and describes how these errors led to the creation of the linear no-threshold (LNT) dose response historically used worldwide for cancer risk assessments for chemical carcinogens and ionizing radiation. The paper demonstrates the significant role that Muller played in the environmental movement, affecting risk assessment policies and practices that are in force even now a half century following his death. This paper lends support to contemporary research that shows significant limitations of the LNT model for cancer risk assessment.
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Affiliation(s)
- Edward J Calabrese
- School of Public Health and Health Sciences, Amherst, MA, 01003, USA; Department of Environmental Health Sciences, Amherst, MA, 01003, USA; Morrill I, N344, Amherst, MA, 01003, USA; University of Massachusetts, Amherst, MA, 01003, USA.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory at Oak Ridge, TN, USA.
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Calabrese EJ. Thresholds for radiation induced mutation? The Muller-Evans debate: A turning point for cancer risk assessment. Chem Biol Interact 2023; 382:110614. [PMID: 37356557 DOI: 10.1016/j.cbi.2023.110614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/20/2023] [Accepted: 06/23/2023] [Indexed: 06/27/2023]
Abstract
In 1949 Robley Evans [1] published a paper in Science supporting a threshold dose response for ionizing radiation-induced mutation, contradicting comments of Hermann Muller during his 1946 Nobel Prize Lecture [2] and subsequent presentations. Evans sent a final draft [3] prior to publication to over 50 leading geneticists/radiologists, including Muller, with this correspondence being generally extremely supportive, including letters from the radiation geneticists Curt Stern, James Neel and Donald Charles. Of interest is that Muller engaged in a dispute with Evans, with Evans dismissing Muller's comments as containing "a few points of scientific interest, and many matters pertaining to personalities and prejudices." A foundation of the Evans threshold position was the study by Ernst Caspari, which was done under the direction of Curt Stern, at the University of Rochester/Manhattan Project, and for which Muller was a paid consultant, thereby having insider knowledge of the research team, results and internal debates. Muller published a series of articles after the Evans Science publication that marginalized the Caspari findings, claiming that his control group was aberrantly high, which caused his threshold conclusion to be incorrect. Internal correspondence in 1947 between Muller and Stern reveals that Muller supported the use of the Caspari control group based on consistency with his own laboratory data. This correspondence shows that Muller reversed his position three years later, soon after the Evans publication. In that same 1947 correspondence with Stern, Muller also claimed that the mutational findings of Delta Uphoff, who was replicating the Caspari study, could not be supported because of aberrantly low control group values only to reverse himself to support the LNT model. The present paper links Muller's threshold rejection/LNT supporting actions to the timing of the debate with Evans concerning Evans' use of the Caspari data to support the threshold model. It is of historical significance that the duplicitous actions of Muller were rewarded, with his newly expressed reversed views becoming generally accepted (while his previously documented contrary views were hidden/remained private). At the same time, the marginalizing of the Caspari findings greatly impacted recommendations to support LNT by major advisory committees.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
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20
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Boretti A. There is no reason to persist in the linear no-threshold (LNT) assumption. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 266-267:107239. [PMID: 37393723 DOI: 10.1016/j.jenvrad.2023.107239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/21/2023] [Accepted: 06/27/2023] [Indexed: 07/04/2023]
Affiliation(s)
- Alberto Boretti
- Johnsonville Road, Johnsonville, Wellington, 6037, New Zealand.
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Laurier D, Billarand Y, Klokov D, Leuraud K. The scientific basis for the use of the linear no-threshold (LNT) model at low doses and dose rates in radiological protection. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2023; 43:024003. [PMID: 37339605 DOI: 10.1088/1361-6498/acdfd7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/20/2023] [Indexed: 06/22/2023]
Abstract
The linear no-threshold (LNT) model was introduced into the radiological protection system about 60 years ago, but this model and its use in radiation protection are still debated today. This article presents an overview of results on effects of exposure to low linear-energy-transfer radiation in radiobiology and epidemiology accumulated over the last decade and discusses their impact on the use of the LNT model in the assessment of radiation-related cancer risks at low doses. The knowledge acquired over the past 10 years, both in radiobiology and epidemiology, has reinforced scientific knowledge about cancer risks at low doses. In radiobiology, although certain mechanisms do not support linearity, the early stages of carcinogenesis comprised of mutational events, which are assumed to play a key role in carcinogenesis, show linear responses to doses from as low as 10 mGy. The impact of non-mutational mechanisms on the risk of radiation-related cancer at low doses is currently difficult to assess. In epidemiology, the results show excess cancer risks at dose levels of 100 mGy or less. While some recent results indicate non-linear dose relationships for some cancers, overall, the LNT model does not substantially overestimate the risks at low doses. Recent results, in radiobiology or in epidemiology, suggest that a dose threshold, if any, could not be greater than a few tens of mGy. The scientific knowledge currently available does not contradict the use of the LNT model for the assessment of radiation-related cancer risks within the radiological protection system, and no other dose-risk relationship seems more appropriate for radiological protection purposes.
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Affiliation(s)
- Dominique Laurier
- Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses, France
| | - Yann Billarand
- Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses, France
| | - Dmitry Klokov
- Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses, France
| | - Klervi Leuraud
- Institute for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses, France
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Cardarelli J. Response to Bahadori. HEALTH PHYSICS 2023; 124:486-490. [PMID: 37114893 DOI: 10.1097/hp.0000000000001691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
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23
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Georgieva M, Vassileva V. Stress Management in Plants: Examining Provisional and Unique Dose-Dependent Responses. Int J Mol Sci 2023; 24:ijms24065105. [PMID: 36982199 PMCID: PMC10049000 DOI: 10.3390/ijms24065105] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/05/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
The purpose of this review is to critically evaluate the effects of different stress factors on higher plants, with particular attention given to the typical and unique dose-dependent responses that are essential for plant growth and development. Specifically, this review highlights the impact of stress on genome instability, including DNA damage and the molecular, physiological, and biochemical mechanisms that generate these effects. We provide an overview of the current understanding of predictable and unique dose-dependent trends in plant survival when exposed to low or high doses of stress. Understanding both the negative and positive impacts of stress responses, including genome instability, can provide insights into how plants react to different levels of stress, yielding more accurate predictions of their behavior in the natural environment. Applying the acquired knowledge can lead to improved crop productivity and potential development of more resilient plant varieties, ensuring a sustainable food source for the rapidly growing global population.
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Nosrati R, Zhang D, Callahan MJ, Shore BJ, Tsai A. Hip Imaging in Children With Cerebral Palsy: Estimation and Intrapatient Comparison of Patient-Specific Radiation Doses of Low-Dose CT and Radiography. Invest Radiol 2023; 58:190-198. [PMID: 36070536 DOI: 10.1097/rli.0000000000000920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Hip displacement is the second most common orthopedic problem affecting children with cerebral palsy (CP). Routine radiographic hip surveillance typically involves an anteroposterior (AP) pelvis radiograph. Unfortunately, this imaging protocol is limited by its projectional technique and the positioning challenges in children with CP. Alternatively, hip low-dose computed tomography (LDCT) has been advocated as a more accurate strategy for imaging surveillance as it provides biofidelic details of the hip that is independent of patient positioning. However, the tradeoff is the (presumed) higher radiation dose to the patient. The goal of this study is to estimate patient-specific radiation doses of hip LDCTs and AP pelvis radiographs in CP patients, and perform an intrapatient dose comparison. MATERIALS AND METHODS A search of our imaging database was performed to identify children with CP who underwent hip LDCT and AP pelvis radiograph within 6 months of each other. The LDCTs were performed using weight-adjusted kVp and tube current modulation, whereas the radiographs were obtained with age-/size-adjusted kVp/mAs. The patient-specific organ and effective doses for LDCT were estimated by matching the patients to a nonreference pediatric phantom library from the National Cancer Institute Dosimetry System for Computed Tomography database with Monte Carlo-based dosimetry. The patient-specific organ and effective doses for radiograph were estimated using the National Cancer Institute Dosimetry System for Radiography and Fluoroscopy with Monte Carlo-based dose calculation. Dose conversion k-factors of dose area product for radiography and dose length product for LDCT were adapted, and the estimation results were compared with patient-specific dosimetry. RESULTS Our study cohort consisted of 70 paired imaging studies from 67 children (age, 9.1 ± 3.3 years). The patient-specific and dose length product-based effective doses for LDCT were 0.42 ± 0.21 mSv and 0.59 ± 0.28 mSv, respectively. The patient-specific and dose area product-based effective doses for radiography were 0.14 ± 0.09 mSv and 0.08 ± 0.06 mSv, respectively. CONCLUSIONS The radiation dose for a hip LDCT is ~4 times higher than pelvis radiograph, but it is still very low and poses minimal risk to the patient.
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Affiliation(s)
| | - Da Zhang
- From the Departments of Radiology
| | | | - Benjamin J Shore
- Orthopedics, Boston Children's Hospital, Harvard Medical School, Boston, MA
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25
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Calabrese EJ, Agathokleous E, Giordano J, Selby PB. Manhattan Project genetic studies: Flawed research discredits LNT recommendations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 319:120902. [PMID: 36566922 DOI: 10.1016/j.envpol.2022.120902] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/28/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
This paper reexamines the technical report (∼ one page) of Uphoff and Stern (1949) in Science that was highly relied upon by the US National Academy of Sciences (NAS) Biological Effects of Atomic Radiation (BEAR) I Genetics Panel to support a linearity dose response for radiation risk assessment. The present paper demonstrates that research of Uphoff and Stern (1949) to evaluate whether total dose or dose rate best estimated radiation risks included two variables, thereby precluding the ability to accurately derive a reliable conclusion about this topic. Furthermore, the acute dose selected by Uphoff and Stern was given at a strikingly low dose rate that may have precluded the capacity to adequately test the total dose/dose rate hypothesis, even with a proper study design which also this research did not possess. The issue of total dose and dose rate was much later successfully addressed by Russell et al. (1958) using a murine model, yielding a dose-rate rather than a total dose conclusion. The failure to subject the experimental details of the Uphoff and Stern (1949) study to peer-review and publication in the open literature precluded a rigorous and necessary evaluation, profoundly and improperly impacting the adoption of the linear dose response model.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences; Morrill I, N344; University of Massachusetts, Amherst, MA, 01003, USA.
| | - Evgenios Agathokleous
- School of Applied Meteorology; Nanjing University of Information Science & Technology, Nanjing, 210044, China.
| | - James Giordano
- Departments of Neurology and Biochemistry, and Pellegrino Center for Clinical Bioethics, Georgetown University Medical Center, Washington, DC, 20007, USA.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory at Oak Ridge, TN, USA; 4088 Nottinghill Gate Road; Upper Arlington, OH, 43220, USA.
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26
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Calabrese EJ. Evolution frames the dose response for all endpoints including application to cancer risk assessment: Time for a mid-course correction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158466. [PMID: 36057310 DOI: 10.1016/j.scitotenv.2022.158466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
An underappreciated perspective is that the quantitative features of the dose-response in the low dose zone are a genetically based biological characteristic with a highly conserved evolutionary basis. Failure to recognize and take this into account has been a major failing of toxicology and radiation biology, affecting regulatory agencies worldwide. The present perspective clarifies the historical foundations of this misstep and calls for a mid- course correction that replaces the public health based Precautionary Principle for risk assessment with one based on the principles of evolutionary biology.
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Affiliation(s)
- Edward J Calabrese
- School of Public Health and Health Sciences, Department of Environmental Health Sciences, University of Massachusetts, Amherst, MA 01003, United States of America.
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27
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Calabrese EJ, Giordano J. Ethical Issues in the US 1956 National Academy of Sciences BEAR I Genetics Panel Report to the Public. HEALTH PHYSICS 2022; 123:387-391. [PMID: 35848926 DOI: 10.1097/hp.0000000000001608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
ABSTRACT This paper presents newly discovered evidence from the personal correspondence of four US National Academy of Sciences (NAS) Biological Effects of Atomic Radiation (BEAR) Genetics Panelists that their 1956 report to the public was written by a third party and was neither reviewed nor approved by the Panel prior to its publication and release to the public. The letters revealed that the 1956 Report contained serious errors and did not represent the views of the Panel. The failure of the US NAS to notify the public that the Report had not been reviewed and approved by the Panel represents a serious breach of ethics. Further ethical issues relate to the failure of the NAS to (1) correct the errors in the Report within an appropriately timely manner and (2) reveal the lack of approval by the Panel even after the Report's release. In light of these discoveries and the profound historical-and continuing-significance of the 1956 Report to all conventional cancer-related risk assessment processes, we opine that this ethical improbity must be acknowledged and that this document must be retracted by the NAS.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003
| | - James Giordano
- Departments of Neurology and Biochemistry and Pellegrino Center for Clinical Bioethics, Georgetown University Medical Center, Washington, DC 2007, or email at
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28
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Agathokleous E, Barceló D, Aschner M, Azevedo RA, Bhattacharya P, Costantini D, Cutler GC, De Marco A, Docea AO, Dórea JG, Duke SO, Efferth T, Fatta-Kassinos D, Fotopoulos V, Ginebreda A, Guedes RNC, Hayes AW, Iavicoli I, Kalantzi OI, Koike T, Kouretas D, Kumar M, Manautou JE, Moore MN, Paoletti E, Peñuelas J, Picó Y, Reiter RJ, Rezaee R, Rinklebe J, Rocha-Santos T, Sicard P, Sonne C, Teaf C, Tsatsakis A, Vardavas AI, Wang W, Zeng EY, Calabrese EJ. Rethinking Subthreshold Effects in Regulatory Chemical Risk Assessments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11095-11099. [PMID: 35878124 DOI: 10.1021/acs.est.2c02896] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Evgenios Agathokleous
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing 210044, Jiangsu China
- Research Center for Global Changes and Ecosystem Carbon Sequestration & Mitigation, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, Jiangsu China
| | - Damià Barceló
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC; Barcelona 08034, Spain
- Catalan Institute for Water Research, ICRA-CERCA; Girona 17003, Spain
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine; Bronx, New York 10461, United States
| | - Ricardo Antunes Azevedo
- Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz"/Universidade de São Paulo (ESALQ/USP); São Paulo CEP 13418-900, Brazil
| | - Prosun Bhattacharya
- KTH-international Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology; Stockholm SE-100 44, Sweden
| | - David Costantini
- Unité Physiologie Moléculaire et Adaptation (PhyMA), UMR 7221 Muséum National d'Histoire Naturelle; CNRS, 7 Rue Cuvier, 75005 Paris, France
| | - G Christopher Cutler
- Department of Plant, Food, and Environmental Sciences, Agricultural Campus, Dalhousie University; Truro, Nova Scotia B2N 5E3, Canada
| | | | - Anca Oana Docea
- Department of Toxicology, University of Medicine and Pharmacy of Craiova; Craiova 200349, Romania
| | - José G Dórea
- Faculdade de Ciências da Saúde, Universidade de Brasília; Brasília 70919-970, Brazil
| | - Stephen O Duke
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi; Mississippi 38677, United States
| | - Thomas Efferth
- Johannes Gutenberg University, Institute of Pharmaceutical and Biomedical Sciences, Department of Pharmaceutical Biology; Mainz 55128, Germany
| | - Despo Fatta-Kassinos
- Department of Civil and Environmental Engineering and Nireas-International Water Research Centre, School of Engineering, University of Cyprus; P.O. Box 20537, Nicosia 1678, Cyprus
| | - Vasileios Fotopoulos
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology; Lemesos 3603, Cyprus
| | - Antonio Ginebreda
- Environmental Chemistry, IDAEA-CSIC, c/Jordi Girona 18-26, Barcelona 08034, Spain
| | - Raul Narciso C Guedes
- Departamento de Entomologia, Universidade Federal de Viçosa;Viçosa, Minas Gerais 36570-900, Brazil
| | - A Wallace Hayes
- Center for Environmental/Occupational Risk Analysis & Management, University of South Florida, College of Public Health; Tampa, Florida 33612, United States
- Michigan State University; East Lansing, Michigan 48824, United States
| | - Ivo Iavicoli
- Department of Public Health, Section of Occupational Medicine, University of Naples Federico II; Naples 80131, Italy
| | | | - Takayoshi Koike
- Research Faculty of Agriculture, Hokkaido University; Sapporo, Hokkaido 060-8589, Japan
| | - Demetrios Kouretas
- Department of Biochemistry-Biotechnology, University of Thessaly, Larisa 41500, Greece
| | - Manish Kumar
- School of Engineering, University of Petroleum and Energy Studies; Dehradun 248007, India
| | - José E Manautou
- Pharmaceutical Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Michael N Moore
- European Centre for Environment & Human Health (ECEHH), University of Exeter Medical School, Knowledge Spa, Royal Cornwall Hospital; Truro TR1 3HD, U.K
- Plymouth Marine Laboratory; Plymouth, Devon PL1 3DH, U.K
- School of Biological & Marine Sciences, University of Plymouth; Plymouth PL 4 8AA, U.K
| | - Elena Paoletti
- Institute of Research on Terrestrial Ecosystems, National Research Council; Sesto Fiorentino 50019, Italy
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB; Bellaterra, Catalonia 08193, Spain
- CREAF; Cerdanyola del Vallès, Catalonia 08193, Spain
| | - Yolanda Picó
- Environmental and Food Safety Research Group (SAMA-UV), Desertification Research Centre (CIDE), Universitat de València-CSIC-GV; Valencia 46113, Spain
| | - Russel J Reiter
- Department of Cell Systems and Anatomy, Joe R. and Teresa Lozano Long School of Medicine, UT Health San Antonio; San Antonio, Texas 78229, United States
| | - Ramin Rezaee
- International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences,Mashhad 91779-43335, Iran
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad 91779-43335, Iran
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water, and Waste-Management, Laboratory of Soil, and Groundwater-Management; Wuppertal 42285, Germany
| | - Teresa Rocha-Santos
- Centre for Environmental and Marine Studies (CESAM) & Department of Chemistry, University of Aveiro; Aveiro 3810-193, Portugal
| | - Pierre Sicard
- ARGANS, 260 route du Pin Montard, Biot 06410, France
| | - Christian Sonne
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC); Roskilde DK-4000, Denmark
- Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University; Zhengzhou 450002, China
| | - Christopher Teaf
- Institute of Science & Public Affairs, Florida State University; Tallahassee, Florida 32306, United States
| | - Aristidis Tsatsakis
- Laboratory of Toxicology, Medical School, University of Crete; Heraklion 71003, Greece
| | - Alexander I Vardavas
- Laboratory of Toxicology, Medical School, University of Crete; Heraklion 71003, Greece
| | - Wenjie Wang
- Key Laboratory of Forest Plant Ecology, Northeast Forestry University; Harbin 150040, China
- Northeast Institute of Geography and Agroecology, Chinese Academy of Science; Changchun 130102, China
| | - Eddy Y Zeng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University; Guangzhou 511443, China
| | - Edward J Calabrese
- Department of Environmental Health Sciences, University of Massachusetts; Amherst, Massachusetts 01003, United States
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Is LNT anti-evolution dose response model? Arch Toxicol 2022; 96:3141-3142. [PMID: 35943540 DOI: 10.1007/s00204-022-03360-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/03/2022] [Indexed: 11/02/2022]
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30
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Linear non-threshold (LNT) fails numerous toxicological stress tests: Implications for continued policy use. Chem Biol Interact 2022; 365:110064. [DOI: 10.1016/j.cbi.2022.110064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/24/2022] [Accepted: 07/18/2022] [Indexed: 11/16/2022]
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Calabrese EJ, Selby PB, Giordano J. Ethical challenges of the linear non-threshold (LNT) cancer risk assessment revolution: History, insights, and lessons to be learned. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 832:155054. [PMID: 35390380 DOI: 10.1016/j.scitotenv.2022.155054] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/01/2022] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
This paper provides historical review and evaluation of the development, adoption, and advocacy of the linear non-threshold (LNT) dose response model for cancer risk assessment as applied in practices and policies worldwide. It extends previous historical assessments and provides novel insights regarding: 1) how LNT bias became institutionalized in US governmental agencies, 2) how improper editorial practices at the journal Science promoted the adoption of LNT, 3) how a Nobel Prize winning scientist unjustifiably espoused and influenced support for replacing the threshold dose response model with the LNT model, 4) how the cover-up of striking and substantial experimental cancer data by US government scientists reduced support for the threshold dose response model at a critical period of cancer risk assessment policy adoption, and 5) how these events have negatively influenced cancer risk assessment practices and environmental and public health decisions for decades. These findings are presented to illustrate how profound and recognized mistakes, biases and unethical activities, inclusive of frank scientific misconduct, converged, and should motivate regulatory agencies worldwide to critically evaluate any existing policies that apply the LNT model as well as to serve as object lessons for current and future ethical conduct of research, and the provision of ethico-legal education in and across scientific curricula and institutions.
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Affiliation(s)
- Edward J Calabrese
- School of Public Health and Health Sciences, Department of Environmental Health Sciences, University of Massachusetts, Morrill I, N344, Amherst, MA 01003, USA.
| | - Paul B Selby
- Retired, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - James Giordano
- Departments of Neurology and Biochemistry and Pellegrino Center for Clinical Bioethics, Georgetown University Medical Center, Washington, DC 20007, USA
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Calabrese EJ, Selby PB. Cover up and cancer risk assessment: Prominent US scientists suppressed evidence to promote adoption of LNT. ENVIRONMENTAL RESEARCH 2022; 210:112973. [PMID: 35182593 DOI: 10.1016/j.envres.2022.112973] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/15/2022] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
This paper reports that William Russell, Oak Ridge National Laboratory (ORNL), conducted a large-scale lifetime study from 1956 to 1959 showing that exposure of young adult male mice to a large dose of acute X-rays had no treatment effects on male and female offspring concerning longevity or the frequency, severity, or age distribution of neoplasms and other diseases. Despite the scientific, societal and crucial timing significance of the study, Russell did not publish the findings for almost 35 years, nor did he inform governmental advisory committees, thereby significantly biasing decisions made during this period which supported the adoption of LNT for risk assessment. Of further significance, Arthur Upton, an ORNL colleague of Russell during this study and later Director of the US National Cancer Institute (NCI), was also fully knowledgeable of this study, its findings and its negative impact on the acceptance of LNT. Upton later worked along with Russell to publish these data (i.e., Cosgrove et al., 1993) to dispute the case-specific claim that children developed cancer because of the radiation exposure of their fathers as workers at the Sellafield nuclear plant. Thus, while Russell's data were available, but were not used to challenge the key radiation and leukemia paper of Edward B. Lewis, (1957) when LNT was being adopted by regulatory agencies, they were used in a major trial in the United Kingdom (UK) for the client (i.e., British Nuclear Fuels Plc) that hired Upton. While the duplicity of Russell's and Upton's actions is striking, the key finding of the present paper is that Russell and Upton intentionally orchestrated and sustained an LNT cover up during the key period of LNT adoption by regulatory agencies, thereby showing an overwhelming bias to enhance the adoption of LNT.
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Affiliation(s)
- Edward J Calabrese
- Professor of Toxicology, School of Public Health and Health Sciences, Department of Environmental Health Sciences, University of Massachusetts, Morrill I, N344, Amherst, MA, 01003, USA.
| | - Paul B Selby
- Retired from Oak Ridge National Laboratory at Oak Ridge, TN.
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Ricci PF, Calabrese EJ. Resolving an Open Science-policy question: Should the LNT still be an omnibus regulatory assumption? THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:153917. [PMID: 35189226 DOI: 10.1016/j.scitotenv.2022.153917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/11/2022] [Accepted: 02/12/2022] [Indexed: 06/14/2023]
Abstract
Regulatory analyses, modeling the carcinogenic effect of ionizing radiations (IR) (e.g., alpha and beta particles, x-, and gamma rays, neutrons) and chemicals continue to use the linear no-threshold (LNT) model from zero to some low dose. The LNT is an omnibus causal default in regulatory occupational and health risk analysis. Its use raises four issues that make this default an open question. The first is that the LNT applied to study a single agent excludes co-exposure to other known risk factors: physical, dietary, socio-economic, and other. Causation is inappropriately specified because cancer incidence is imputed to the single agent's doses, although most cancers are multifactorial diseases. The second, linear interpolation from high to zero dose and response, is incorrect because biological and epidemiological evidence identify different mechanisms and modes of action at those doses. Third, additivity of exposure effect to background effect is questionable and certainly variable. Fourth, the default overestimates the probabilities and consequences at low doses, supplanting rational decision-making in which alternative models may be more or less likely to be correct. Recent converging scientific evidence against the LNT hypothesis answers the open question. The LNT use in regulation conflates science with administrative ease and risk aversion by policymakers. It should be replaced by models that are based on biologically motivated mechanistic understandings within an evolutionary biology framework that integrates adaptive strategies/processes in their formulation.
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Affiliation(s)
- Paolo F Ricci
- University of Bologna, Environmental Management, Ravenna Campus, Scienze Ambientali, Via Sant'Alberto 163, 48123, Ravenna, Italy.
| | - Edward J Calabrese
- Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003, USA.
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Jargin S. Exaggerated Risk Perception of Low-Dose Radiation: Motives and Mechanisms. Dose Response 2022; 20:15593258221103378. [PMID: 35602581 PMCID: PMC9121466 DOI: 10.1177/15593258221103378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 05/03/2022] [Indexed: 11/16/2022] Open
Affiliation(s)
- Sergei Jargin
- Peoples’ Friendship University of Russia, Moskva, Russia
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35
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LNTgate: How LNT benefited from editorial actions. Chem Biol Interact 2022; 362:109979. [PMID: 35594956 DOI: 10.1016/j.cbi.2022.109979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 04/26/2022] [Accepted: 05/06/2022] [Indexed: 11/23/2022]
Abstract
This paper illustrates how the acceptance of the linear non-threshold (LNT) dose response model was unethically advocated and advanced both by key scientists within the radiation genetics community, and by editorial practices in Science, a leading international scientific journal. Four key papers became the cornerstones in the acceptance of the LNT model. In the publication process of these papers, editorial decisions to circumvent peer review occurred in at least two cases. As well, the summarized data of one paper were never shared with the scientific community and remain missing to date. Publication of a paper in Science on which a senior editor of the journal was a co-author is alleged to have intentionally falsified the research record (BEAR Genetics Panel). These findings raise the question of whether foundational papers for major contemporary regulatory policy (i.e., LNT/cancer risk assessment) that lack scientific legitimacy, as identified herein, should be retracted. These findings also should serve as the basis for considerable ethical concern, as well as a prompt for ongoing ethical diligence and rigor in the conduct and publication of scientific research.
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Porrazzo A, Esposito G, Grifoni D, Cenci G, Morciano P, Tabocchini MA. Reduced Environmental Dose Rates Are Responsible for the Increased Susceptibility to Radiation-Induced DNA Damage in Larval Neuroblasts of Drosophila Grown inside the LNGS Underground Laboratory. Int J Mol Sci 2022; 23:ijms23105472. [PMID: 35628279 PMCID: PMC9143493 DOI: 10.3390/ijms23105472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 02/04/2023] Open
Abstract
A large amount of evidence from radiobiology studies carried out in Deep Underground Laboratories support the view that environmental radiation may trigger biological mechanisms that enable both simple and complex organisms to cope with genotoxic stress. In line with this, here we show that the reduced radiation background of the LNGS underground laboratory renders Drosophila neuroblasts more sensitive to ionizing radiation-induced (but not to spontaneous) DNA breaks compared to fruit flies kept at the external reference laboratory. Interestingly, we demonstrate that the ionizing radiation sensitivity of flies kept at the LNGS underground laboratory is rescued by increasing the underground gamma dose rate to levels comparable to the low-LET reference one. This finding provides the first direct evidence that the modulation of the DNA damage response in a complex multicellular organism is indeed dependent on the environmental dose rate.
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Affiliation(s)
- Antonella Porrazzo
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, 00185 Rome, Italy; (A.P.); (G.C.)
| | - Giuseppe Esposito
- Centro Nazionale per le Tecnologie Innovative in Sanità Pubblica (TISP), Istituto Superiore di Sanità (ISS), 00161 Rome, Italy;
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione Roma 1, 00185 Rome, Italy
- Correspondence: (G.E.); (P.M.)
| | - Daniela Grifoni
- Dipartimento di Medicina Clinica, Sanità Pubblica, Scienze Della Vita e Dell’ambiente, Università Dell’aquila, 67100 L’Aquila, Italy;
| | - Giovanni Cenci
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Sapienza Università di Roma, 00185 Rome, Italy; (A.P.); (G.C.)
- Fondazione Cenci Bolognetti, Istituto Pasteur, 00185 Rome, Italy
| | - Patrizia Morciano
- Laboratori Nazionali del Gran Sasso (LNGS), INFN, Assergi, 67100 L’Aquila, Italy
- Correspondence: (G.E.); (P.M.)
| | - Maria Antonella Tabocchini
- Centro Nazionale per le Tecnologie Innovative in Sanità Pubblica (TISP), Istituto Superiore di Sanità (ISS), 00161 Rome, Italy;
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione Roma 1, 00185 Rome, Italy
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Dzul S, Jaenisch H, Nagle C, Joiner M, Miller S. Radiation induced mucoepidermoid carcinoma of the parotid gland following post-operative radiotherapy to the earlobe for keloid prophylaxis. EAR, NOSE & THROAT JOURNAL 2022:1455613221099998. [PMID: 35503458 DOI: 10.1177/01455613221099998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Radiation-induced malignancies (RIMs) are rare but well-documented late toxicities associated with exposure to radiation or radiotherapy. A keloid scar is a common benign proliferation of scar tissue which commonly develops at the site of an injury, such as on the earlobe after ear-piercing. While typically reserved for management of malignancies, radiotherapy is often utilized in the management of some benign conditions, including keloids. Given the benign nature of keloids, any theoretical late toxicity from radiotherapy, particularly a life-threatening toxicity such as a RIM, is particularly concerning. Here, we report a case of a 34-year-old male who presented with a radiation induced mucoepidermoid carcinoma of the parotid gland which developed in a previously irradiated field ten years after the patient received electron radiotherapy for a keloid of the earlobe. Using available literature, we estimate the risk of a RIM of the parotid gland from a typical course of radiotherapy to the earlobe as 0.007% per year.
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Affiliation(s)
- Stephen Dzul
- Department of Radiation Oncology, 2954Wayne State University, Detroit, MI, USA
| | - Harriett Jaenisch
- Department of Radiation Oncology, 2954Wayne State University, Detroit, MI, USA
| | - Chris Nagle
- Department of Radiation Oncology, 2954Wayne State University, Detroit, MI, USA
| | - Michael Joiner
- Department of Radiation Oncology, 2954Wayne State University, Detroit, MI, USA
| | - Steven Miller
- Department of Radiation Oncology, 2954Wayne State University, Detroit, MI, USA
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Hurlbert M, Shasko L, Neetz MI. Addressing Risk Perceptions of Low-Dose Radiation Exposure. Dose Response 2022; 20:15593258221088428. [PMID: 35418815 PMCID: PMC8995549 DOI: 10.1177/15593258221088428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/28/2022] [Indexed: 02/01/2023] Open
Abstract
Concern over low-dose radiation (LDR) (exposure of less than 100 milligray (mGy))
is resulting in people refusing diagnostic procedures and medical treatment1 and also inhibiting revision of the linear no-threshold (LNT) assumption
that informs much of science policy. This article reviews representative surveys
in Ontario and Saskatchewan and focus groups conducted with science and policy
stakeholders in addressing how the public and policy stakeholders understand
issues of exposure to LDR and how policy issues can be addressed. Research results from focus groups demonstrated that policy stakeholders are
knowledgeable about issues surrounding the public and perceptions about LDR and
implications for policy consistent with LDR literature. Participants understood
that the challenge went beyond providing more education about LDR and issues of
emotions and biases must be addressed. This research resulted in rich
suggestions for public communication and engagement surrounding LDR and a
process for addressing the issue of the LNT.
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Affiliation(s)
| | - Larissa Shasko
- Johnson Shoyama Graduate School of Public Policy, Saskatoon, Canada
| | - MIchaela Neetz
- Johnson Shoyama Graduate School of Public Policy, Saskatoon, Canada
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Calabrese EJ. Key historical study findings questioned in debate over threshold versus linear non-threshold for cancer risk assessment. Chem Biol Interact 2022; 359:109917. [DOI: 10.1016/j.cbi.2022.109917] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/18/2022] [Accepted: 03/23/2022] [Indexed: 11/27/2022]
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Sebastiano M, Messina S, Marasco V, Costantini D. Hormesis in ecotoxicological studies: a critical evolutionary perspective. CURRENT OPINION IN TOXICOLOGY 2022. [DOI: 10.1016/j.cotox.2022.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Krishan M, Navarro L, Beck B, Carvajal R, Dourson M. A regulatory relic: After 60 years of research on cancer risk, the Delaney Clause continues to keep us in the past. Toxicol Appl Pharmacol 2021; 433:115779. [PMID: 34737146 DOI: 10.1016/j.taap.2021.115779] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/23/2021] [Accepted: 10/25/2021] [Indexed: 11/29/2022]
Abstract
The Delaney Clause of the Federal Food, Drug, and Cosmetic Act became law in 1958 because of concerns that potentially harmful chemicals were finding their way into foods and causing cancer. It states, "[n]o additive shall be deemed to be safe if it is found to induce cancer when ingested by man or animal, or if it is found, after tests which are appropriate for the evaluation of the safety of food additives, to induce cancer in man or animal." The United States Food and Drug Administration (US FDA) and United States Environmental Protection Agency (US EPA, prior to implementation of the Food Quality Protection Act) were charged with implementing this clause. Over 60 years, advances in cancer research have elucidated how chemicals induce cancer. Significant advancements in analytical methodologies have allowed for accurate and progressively lower detection limits, resulting in detection of trace amounts. Based on current scientific knowledge, there is a need to revisit the Delaney Clause's utility. The lack of scientific merit to the Delaney Clause was very apparent when recently the US FDA had to revoke the food additive approvals of 6 synthetic flavoring substances because high dose testing in animals demonstrated a carcinogenic response. However, US FDA determined that these 6 synthetic flavoring substances do not pose a risk to public health under the conditions of intended use. The 7th substance, styrene, was de-listed because it is no longer used by industry. The scientific community is committed to improving public health by promoting relevant science in risk assessment and regulatory decision making, and this was discussed in scientific sessions at the American Association for the Advancement of Science (AAAS) 2020 Annual Meeting and the Society of Toxicology (SOT) 2019 Annual Meeting. Expert presentations included advances in cancer research since the 1950s; the role of the Delaney Clause in the current regulatory paradigm with a focus on synthetic food additives; and the impact of the clause on scientific advances and regulatory decision making. The sessions concluded with panel discussions on making the clause more relevant based on 21st-century science.
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Cuttler JM, Calabrese EJ. What Would Become of Nuclear Risk if Governments Changed Their Regulations to Recognize the Evidence of Radiation's Beneficial Health Effects for Exposures That Are Below the Thresholds for Detrimental Effects? Dose Response 2021; 19:15593258211059317. [PMID: 34880717 PMCID: PMC8647278 DOI: 10.1177/15593258211059317] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The 1953 Atoms for Peace Speech to the United Nations proposed applying nuclear energy to essential needs, including abundant electrical energy. The widespread fear of ionizing radiation from nuclear facilities and medical procedures began after the United States National Academy of Sciences performed a study of radiation dangers to the human genome. This study, initiated and managed by an oil industry benefactor, recommended in 1956 that the risk of radiation-induced mutations be assessed using the linear no-threshold dose-response model instead of the threshold model. It was followed by a study that wrongly linked low radiation to cancer among the atomic bomb survivors. The ensuing controversy resulted in a compromise. The National Committee on Radiation Protection adopted the precautionary principle policy in 1959, justified by fear of cancer and lack of knowledge. The United States and all other countries followed this recommendation, which remains unchanged 62 years later. Its impact on nuclear energy and medicine has been profound. Many costly regulations have been enacted to prevent very unlikely human or equipment failures-failures that would lead to radiation exposures that are below the dose thresholds for lasting harmful effects. Potential low-dose radiation therapies, against inflammation, cancer, autoimmune, and neurodegenerative diseases, are shunned.
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Affiliation(s)
| | - Edward J. Calabrese
- Department of Environmental Health
Sciences, University of Massachusetts Amherst, Amherst, MA, USA
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Agathokleous E, Barceló D, Calabrese EJ. US EPA: Is there room to open a new window for evaluating potential sub-threshold effects and ecological risks? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 284:117372. [PMID: 34087668 DOI: 10.1016/j.envpol.2021.117372] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/08/2021] [Accepted: 05/04/2021] [Indexed: 05/17/2023]
Abstract
With a rule published on 6 January 2021, the US Environmental Protection Agency (EPA) considers for the first time sub-threshold responses, abandoning the use of default dose-response models. This may affect worldwide scientific research, in terms of research design and methodology, and regulatory actions in China and other countries.
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Affiliation(s)
- Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, Department of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology (NUIST), Nanjing, 210044, China.
| | - Damià Barceló
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, C/ Jordi Girona 18-26, 08034, Barcelona, Spain; Catalan Institute for Water Research, ICRA-CERCA, Emili Grahit 101, 17003, Girona, Spain
| | - Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA
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Calabrese EJ, Agathokleous E. Hormesis: Transforming disciplines that rely on the dose response. IUBMB Life 2021; 74:8-23. [PMID: 34297887 DOI: 10.1002/iub.2529] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 06/28/2021] [Indexed: 12/16/2022]
Abstract
This article tells the story of hormesis from its conceptual and experimental origins, its dismissal by the scientific and medical communities in the first half of the 20th century, and its rediscovery over the past several decades to be a fundamental evolutionary adaptive strategy. The upregulation of hormetic adaptive mechanisms has the capacity to decelerate the onset and reduce the severity of a broad spectrum of common age-related health, behavioral, and performance decrements and debilitating diseases, thereby significantly enhancing the human health span. Incorporation of hormetic-based lifestyle options within the human population would have profoundly positive impacts on the public health, significantly reducing health care costs.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I-N344, University of Massachusetts, Amherst, Massachusetts, USA
| | - Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, Department of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology (NUIST), Nanjing, China
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Khan AUH, Blimkie M, Yang DS, Serran M, Pack T, Wu J, Kang JY, Laakso H, Lee SH, Le Y. Effects of Chronic Low-Dose Internal Radiation on Immune-Stimulatory Responses in Mice. Int J Mol Sci 2021; 22:7303. [PMID: 34298925 PMCID: PMC8306076 DOI: 10.3390/ijms22147303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/01/2021] [Accepted: 07/01/2021] [Indexed: 12/18/2022] Open
Abstract
The Linear-No-Threshold (LNT) model predicts a dose-dependent linear increase in cancer risk. This has been supported by biological and epidemiological studies at high-dose exposures. However, at low-doses (LDR ≤ 0.1 Gy), the effects are more elusive and demonstrate a deviation from linearity. In this study, the effects of LDR on the development and progression of mammary cancer in FVB/N-Tg(MMTVneu)202Mul/J mice were investigated. Animals were chronically exposed to total doses of 10, 100, and 2000 mGy via tritiated drinking water, and were assessed at 3.5, 6, and 8 months of age. Results indicated an increased proportion of NK cells in various organs of LDR exposed mice. LDR significantly influenced NK and T cell function and activation, despite diminishing cell proliferation. Notably, the expression of NKG2D receptor on NK cells was dramatically reduced at 3.5 months but was upregulated at later time-points, while the expression of NKG2D ligand followed the opposite trend, with an increase at 3.5 months and a decrease thereafter. No noticeable impact was observed on mammary cancer development, as measured by tumor load. Our results demonstrated that LDR significantly influenced the proportion, proliferation, activation, and function of immune cells. Importantly, to the best of our knowledge, this is the first report demonstrating that LDR modulates the cross-talk between the NKG2D receptor and its ligands.
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Affiliation(s)
- Abrar Ul Haq Khan
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (A.U.H.K.); (D.S.Y.); (J.-Y.K.)
| | - Melinda Blimkie
- Radiobiology and Health Branch, Canadian Nuclear Laboratories Ltd., Chalk River, ON K0J 1J0, Canada; (M.B.); (M.S.); (T.P.); (J.W.); (H.L.)
| | - Doo Seok Yang
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (A.U.H.K.); (D.S.Y.); (J.-Y.K.)
| | - Mandy Serran
- Radiobiology and Health Branch, Canadian Nuclear Laboratories Ltd., Chalk River, ON K0J 1J0, Canada; (M.B.); (M.S.); (T.P.); (J.W.); (H.L.)
| | - Tyler Pack
- Radiobiology and Health Branch, Canadian Nuclear Laboratories Ltd., Chalk River, ON K0J 1J0, Canada; (M.B.); (M.S.); (T.P.); (J.W.); (H.L.)
| | - Jin Wu
- Radiobiology and Health Branch, Canadian Nuclear Laboratories Ltd., Chalk River, ON K0J 1J0, Canada; (M.B.); (M.S.); (T.P.); (J.W.); (H.L.)
| | - Ji-Young Kang
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (A.U.H.K.); (D.S.Y.); (J.-Y.K.)
| | - Holly Laakso
- Radiobiology and Health Branch, Canadian Nuclear Laboratories Ltd., Chalk River, ON K0J 1J0, Canada; (M.B.); (M.S.); (T.P.); (J.W.); (H.L.)
| | - Seung-Hwan Lee
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (A.U.H.K.); (D.S.Y.); (J.-Y.K.)
- Centre for Infection, The University of Ottawa, Immunity and Inflammation, Ottawa, ON K1H 8M5, Canada
| | - Yevgeniya Le
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (A.U.H.K.); (D.S.Y.); (J.-Y.K.)
- CANDU Owners Group Inc., Toronto, ON M5G 2K4, Canada
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Calabrese EJ. LNT and cancer risk assessment: Its flawed foundations part 1: Radiation and leukemia: Where LNT began. ENVIRONMENTAL RESEARCH 2021; 197:111025. [PMID: 33744270 DOI: 10.1016/j.envres.2021.111025] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/12/2021] [Accepted: 03/13/2021] [Indexed: 06/12/2023]
Abstract
This paper evaluates the scientific basis for the adoption of the linear non-threshold (LNT) dose response model for radiation-induced leukemia. This LNT risk assessment application for leukemia is significant because it: (1) was generalized for all tumor types induced by ionizing radiation and chemical carcinogens at relatively high doses and; (2) it was based on the mechanistic assumption of low dose linearity for somatic cell mutations as determined from responses in mature spermatozoa of fruit flies. A serious problem with the latter assumption is that those spermatozoa lack DNA repair. The acceptance of the LNT dose response model for cancer risk assessment was based on the convergence of recommendations of the BEAR I Genetics Panel (1956a) for reproductive cell gene mutations and those of Lewis (1957a) for somatic cell mutation and its capacity to explain apparent and/or predicted linear dose responses of ionizing radiation-induced leukemia in multiple and diverse epidemiological investigations. Use of that model and related dose response beliefs achieved rapid, widespread and enduring acceptance in the scientific and regulatory communities. They provide the key historical foundation for the sustained LNT-based policy for cancer risk assessment to the present. While previous papers in this series have challenged key scientific assessments and ethical foundations of the BEAR I Genetics Panel, the present paper provides evidence that Lewis: 1) incorrectly interpreted the fundamental scientific studies used to support the LNT conclusion even though such studies show consistent hormetic-J-shaped dose response relationships for leukemia in Hiroshima and Nagasaki survivors; and, 2) demonstrated widespread bias in support of an LNT conclusion and related policies, which kept him from making an objective and fair assessment. The LNT recommendation appears to have been uncritically accepted and integrated into scientific and regulatory practice in large part because it inappropriately appealed to existing authority and it garnered the support of those who were willing to risk greatly exaggerating the public's fears of environmentally-induced disease, such as enhanced risk of leukemia, with the goal of stopping the atmospheric testing of atomic bombs. Adoption of the LNT recommendation demonstrated extensive penetration of ideological influence affecting governmental, scientific and regulatory evaluation at the highest levels in the United States. This paper demonstrates that the scientific foundations for cancer risk assessment were inappropriately and inaccurately assessed, unethically adopted and require significant historical, scientific and regulatory remediation.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
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47
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Calabrese EJ. LNT and cancer risk assessment: Its flawed foundations part 2: How unsound LNT science became accepted. ENVIRONMENTAL RESEARCH 2021; 197:111041. [PMID: 33794170 DOI: 10.1016/j.envres.2021.111041] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/12/2021] [Accepted: 03/13/2021] [Indexed: 06/12/2023]
Abstract
This paper argues that Edward B. Lewis served as a type of independent academic radiation LNT-cancer risk assessment-stalking horse for the BEAR Genetics Panel, a task for which he had no expertise or experience (e.g. radiation, leukemia, epidemiology and statistical modelling). His efforts produced an insufficiently documented, strongly biased, and high-profile paper in Science (May 17, 1957), whose principal conclusions had not been proven, he asserted privately, in writing. This inconclusive perspective was well camouflaged in the published paper by means of sophisticated wordsmithing. At the time his academic department head George Beadle came to chair the BEAR Genetics Panel in the summer of 1956, the Beadle-inspired-Lewis LNT activity acquired an urgency when a study of 70,000 offspring from survivors of the A-bombs failed to show genetic damage after a decade of careful study, undercutting Panel recommendations. With Beadle's guidance, the Lewis effort redirected the Panel's focus from the atomic bomb genetic damage study, which had acrimoniously disrupted Panel relationships and priorities, to more immediate disciplinary/professional opportunities with concerns about fallout, leukemia risks and a new cancer causation role for mutation. The serious limitations of the Lewis paper affected neither its publication in Science nor its receiving an editorial endorsement, possibly due to influence by powerful Panel members, such as Bentley Glass, one of only six senior editors for Science. The Science publication restored, even though improperly, the scientific and moral initiatives of the Panel and led directly to multiple high level LNT recommendations for cancer risk assessment based on the Precautionary Principle, which Lewis asserted, and which remains in place today in essentially all countries. The present paper explores how such a scientific long-shot and quasi-stalking horse, who was unsupported by BEAR Panel members during the withering criticism prompted by his Science article, nevertheless endured in the pursuit of his LNT goal, becoming strikingly successful in achieving a global cancer risk assessment revolution which remains in place.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA, 01003, USA.
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Calabrese EJ, Kozumbo WJ, Kapoor R, Dhawan G, Lara PC, Giordano J. Nrf2 activation putatively mediates clinical benefits of low-dose radiotherapy in COVID-19 pneumonia and acute respiratory distress syndrome (ARDS): Novel mechanistic considerations. Radiother Oncol 2021; 160:125-131. [PMID: 33932453 PMCID: PMC8080499 DOI: 10.1016/j.radonc.2021.04.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/13/2022]
Abstract
Novel mechanistic insights are discussed herein that link a single, nontoxic, low-dose radiotherapy (LDRT) treatment (0.5–1.0 Gy) to (1) beneficial subcellular effects mediated by the activation of nuclear factor erythroid 2-related transcription factor (Nrf2) and to (2) favorable clinical outcomes for COVID-19 pneumonia patients displaying symptoms of acute respiratory distress syndrome (ARDS). We posit that the favorable clinical outcomes following LDRT result from potent Nrf2-mediated antioxidant responses that rebalance the oxidatively skewed redox states of immunological cells, driving them toward anti-inflammatory phenotypes. Activation of Nrf2 by ionizing radiation is highly dose dependent and conforms to the features of a biphasic (hormetic) dose–response. At the cellular and subcellular levels, hormetic doses of <1.0 Gy induce polarization shifts in the predominant population of lung macrophages, from an M1 pro-inflammatory to an M2 anti-inflammatory phenotype. Together, the Nrf2-mediated antioxidant responses and the subsequent shifts to anti-inflammatory phenotypes have the capacity to suppress cytokine storms, resolve inflammation, promote tissue repair, and prevent COVID-19-related mortality. Given these mechanistic considerations—and the historical clinical success of LDRT early in the 20th century—we opine that LDRT should be regarded as safe and effective for use at almost any stage of COVID-19 infection. In theory, however, optimal life-saving potential is thought to occur when LDRT is applied prior to the cytokine storms and before the patients are placed on mechanical oxygen ventilators. The administration of LDRT either as an intervention of last resort or too early in the disease progression may be far less effective in saving the lives of ARDS patients.
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Affiliation(s)
| | | | - Rachna Kapoor
- Saint Francis Hospital and Medical Center, Hartford, USA
| | - Gaurav Dhawan
- Sri Guru Ram Das University of Health Sciences, Amritsar, India.
| | - Pedro C Lara
- Department of Radiation Oncology, Hospital Universitario San Roque, Universidad Fernando Pessoa Canarias, Las Palmas Gran Canaria, Spain.
| | - James Giordano
- Departments of Neurology and Biochemistry, Georgetown University Medical Center, Washington, DC, USA.
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Cohen JM, Beck BD, Rhomberg LR. Historical perspective on the role of cell proliferation in carcinogenesis for DNA-reactive and non-DNA-reactive carcinogens: Arsenic as an example. Toxicology 2021; 456:152783. [PMID: 33872731 DOI: 10.1016/j.tox.2021.152783] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/07/2021] [Accepted: 04/11/2021] [Indexed: 10/21/2022]
Abstract
Our understanding of the etiology of cancer has developed significantly over the past fifty years, beginning with a single-hit linear no-threshold (LNT) conceptual model based on early studies conducted in Drosophila. Over the past several decades, multiple lines of evidence have accumulated to support a contemporary model of chemical carcinogenesis: a multi-hit model involving a prolonged stress environment that over time may drive the mutation of multiple cells into an injured state that ultimately could lead to uncontrolled proliferation via clonal expansion of mutation-carrying daughter cells. Arsenic carcinogenicity offers a useful case study for further exploration of advanced conceptual models for chemical carcinogenesis. A threshold for arsenic carcinogenicity is supported by its mode of action, characterized by repeating cycles of cytotoxicity and cellular regeneration. Furthermore, preliminary meta-analyses of epidemiology dose-response data for inorganic arsenic (iAs) and bladder cancer, correlated to dose-response data measured in vitro, support a threshold of effect in humans on the order of 50-100 μg/L in drinking water. In light of recent developments in our understanding of cancer etiology, we urge strong consideration of the existing mode-of-action evidence supporting a threshold of effect for arsenic carcinogenicity, as well as consideration of the potential methodological pitfalls in evaluating epidemiology dose-response data that could potentially bias in the direction of low-dose linearity.
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Thresholds for carcinogens. Chem Biol Interact 2021; 341:109464. [PMID: 33823170 DOI: 10.1016/j.cbi.2021.109464] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/28/2021] [Accepted: 03/29/2021] [Indexed: 02/07/2023]
Abstract
Current regulatory cancer risk assessment principles and practices assume a linear dose-response relationship-the linear no-threshold (LNT) model-that theoretically estimates cancer risks occurring following low doses of carcinogens by linearly extrapolating downward from experimentally determined risks at high doses. The two-year rodent bioassays serve as experimental vehicles to determine the high-dose cancer risks in animals and then to predict, by extrapolation, the number of carcinogen-induced tumors (tumor incidence) that will arise during the lifespans of humans who are exposed to environmental carcinogens at doses typically orders of magnitude below those applied in the rodent assays. An integrated toxicological analysis is conducted herein to reconsider an alternative and once-promising approach, tumor latency, for estimating carcinogen-induced cancer risks at low doses. Tumor latency measures time-to-tumor following exposure to a carcinogen, instead of tumor incidence. Evidence for and against the concept of carcinogen-induced tumor latency is presented, discussed, and then examined with respect to its relationship to dose, dose rates, and the dose-related concepts of initiation, tumor promotion, tumor regression, tumor incidence, and hormesis. Considerable experimental evidence indicates: (1) tumor latency (time-to-tumor) is inversely related to the dose of carcinogens and (2) lower doses of carcinogens display quantifiably discrete latency thresholds below which the promotion and, consequently, the progression and growth of tumors are delayed or prevented during a normal lifespan. Besides reconciling well with the concept of tumor promotion, such latency thresholds also reconcile favorably with the existence of thresholds for tumor incidence, the stochastic processes of tumor initiation, and the compensatory repair mechanisms of hormesis. Most importantly, this analysis and the arguments presented herein provide sound theoretical, experimental, and mechanistic rationales for rethinking the foundational premises of low-dose linearity and updating the current practices of cancer risk assessment to include the concept of carcinogen thresholds.
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