Доступ предоставлен для: Guest
Портал Begell Электронная Бибилиотека e-Книги Журналы Справочники и Сборники статей Коллекции
Journal of Environmental Pathology, Toxicology and Oncology
Импакт фактор: 1.241 5-летний Импакт фактор: 1.349 SJR: 0.356 SNIP: 0.613 CiteScore™: 1.61

ISSN Печать: 0731-8898
ISSN Онлайн: 2162-6537

Journal of Environmental Pathology, Toxicology and Oncology

DOI: 10.1615/JEnvironPatholToxicolOncol.v20.i1.90
6 pages

Combined Effect of Radiation and Other Agents: Is There a Synergism Trap?

W. Burkart
BfS Institute of Radiation Hygiene, Ingolstadter Landstr. 1, D-85764 Oberschleissheim, Munich, Germany

Краткое описание

Most assessments of possible deleterious outcomes from environmental and occupational exposures concentrate on single agents and neglect the potential for combined effects—that is, synergisms or antagonisms. Biomechanistic considerations based on multistep processes, such as carcinogenesis, indicate the potential for highly detrimental interactions if two or more consecutive rate-limiting steps are specifically effected by different agents. However, low specificity toward molecular structure or DNA sequence—and, therefore, exchangeability—of many genotoxic agents indicate little functional specificity and, hence, little vulnerability toward synergism in most occupational and environmental exposure situations. It is also evident that a low potential exists for the combined effects of common low-exposure situations wherein nongenotoxic agents with highly nonlinear dose-effect relationships and apparent thresholds are involved. A quantitative assessment of the contribution of synergistic interactions to the total detriment from natural and man-made toxicants based on experimental data is far away.
There are important examples of combined exposures shown to lead to health effect risks that differ from those expected from simple addition —for example, the influence of smoking on radon- or asbestosinduced lung cancer and on ethanol-induced esophageal cancer. The existing data on combined effects is rudimentary, mainly descriptive, and rarely covers exposure ranges large enough to make direct inferences to present-day low-dose exposure situations. In view of the multitude of possible interactions among the large number of potentially harmful agents in the human environment, descriptive approaches will have to be supplemented by the use of mechanistic models for critical health endpoints, such as cancer. Finally, considering the shape of dose-effect relationships for ionizing radiation, an important question arises from the unresolved question of whether real or apparent thresholds may be used for any genotoxic agent, separately or one time, for an exposed genome.


Articles with similar content:

Relevance of Radioprotectors in Radiotherapy: Studies with Tocopherol Monoglucoside
Journal of Environmental Pathology, Toxicology and Oncology, Vol.23, 2004, issue 2
Rema Rajagopalan, Cherupally Krishnan Krishnan Nair, Tsutomu V. Kagiya, Veena Salvi
Correlation of Apoptosis with Comet Formation Induced by Tea Polyphenols in Human Leukemia Cells
Journal of Environmental Pathology, Toxicology and Oncology, Vol.24, 2005, issue 2
Maqsood Siddiqi, Madhumita Roy, Trina Kundu, Rathindra Kumar Bhattacharya
Ethical Considerations for Psychiatry in the Broadening Scope of Medical Marijuana Therapy (correct)
Ethics in Biology, Engineering and Medicine: An International Journal, Vol.2, 2011, issue 1
Laurie E. Gordon
Evaluation of Genotoxicity of Medicinal Plant Extracts by the Comet and VITOTOX® Tests
Journal of Environmental Pathology, Toxicology and Oncology, Vol.24, 2005, issue 3
Saroj Arora, Swayamjot Kaur, Ethel Brits, Kamaljit Kaur, Subodh Kumar, Luc Verschaeve, Rajbir S. Sohi
Abstract of "Researchers Must Review Informed Consent Laws' New Decisions"
Journal of Long-Term Effects of Medical Implants, Vol.18, 2008, issue 1
Milton Palat