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Radiation, ecology and the invalid LNT model: the evolutionary imperative.
1La Trobe University, Victoria, Australia. pparsons@internode.on.net
Summary
Organisms prioritize metabolic efficiency for survival, challenging the linear-no threshold model for environmental risks. This evolutionary principle supports hormesis and non-linear models for radiation risk assessment.
Area of Science:
- Evolutionary Biology
- Environmental Science
- Radiation Biology
Background:
- Organismal fitness is linked to maximal metabolic and energetic efficiency in habitats.
- The linear-no threshold (LNT) model is challenged by evolutionary principles.
- Oxidative stress is a significant factor in adaptation to stressed environments.
Purpose of the Study:
- To evaluate the validity of the LNT model for environmental agents.
- To explore the universality of hormesis as an adaptive response.
- To establish a non-linear risk assessment model for low-dose ionizing radiation based on evolutionary imperatives.
Main Methods:
- Review of evolutionary biology tenets regarding metabolic efficiency.
- Analysis of radiation hormetic zones in relation to abiotic stresses.
- Examination of demographic and experimental data supporting non-linear dose-response relationships.
Main Results:
- Hormesis is proposed as a universal adaptive response to environmental stress.
- Radiation hormetic zones can be explained by interactions among multiple abiotic stresses.
- Demographic and experimental data largely support non-linear dose-response models.
Conclusions:
- The LNT model is invalidated by evolutionary biology principles.
- Non-linearity is the primary model for assessing low-dose ionizing radiation risks.
- Risk assessment for radiation should be based on the evolutionary imperative for metabolic efficiency.
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