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Origin of the linearity no threshold (LNT) dose-response concept
1Department of Public Health, Environmental Health Sciences, University of Massachusetts, Morrill I, N344, Amherst, MA, 01003, USA. edwardc@schoolph.umass.edu
Archives of Toxicology
|July 27, 2013
Summary
The linear no-threshold (LNT) concept for radiation mutation originated from early 20th-century studies. Biophysical models and mutation data integrated to form the LNT model, influencing radiation risk assessment.
Area of Science:
- Radiation genetics
- Biophysics
- Evolutionary biology
Background:
- Early 20th-century research explored X-ray-induced mutations and their role in evolution.
- The initial hypothesis proposed radiation-induced mutations as a primary driver of heritable traits and evolution.
- A linear dose-response relationship was assumed for genetic damage to support this evolutionary concept.
Observation:
- Olson and Lewis (1928) proposed radiation-induced mutations as a mechanism for heritable traits and evolution.
- Subsequent studies by Hanson and Heys (1929) and Oliver (1930) suggested a linear dose response for radiation-induced mutations.
- Muller's work with Drosophila indicated background radiation had minimal impact on spontaneous mutation, challenging the evolutionary hypothesis.
Findings:
- Collaboration between physicists and geneticists led to integrated biophysical models.
- The development of a gene target theory and single-hit hypothesis provided a mechanism for radiation-induced mutation.
- These advancements established the theoretical and mathematical foundation for the linear no-threshold (LNT) model.
Implications:
- The LNT concept became widely accepted by radiation geneticists and advisory committees for risk assessment.
- It has been applied to assess risks from ionizing radiation-induced mutational damage and cancer.
- The LNT model's principles were later extended to chemical carcinogen risk assessment globally.
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