Related Experiment Video
Updated: Jun 19, 2026
10:24
Neutron Radiography and Computed Tomography of Biological Systems at the Oak Ridge National Laboratory's High Flux Isotope Reactor
Published on: May 7, 2021
THE COMPARATIVE EFFECTS OF NEUTRONS AND X-RAYS ON THE WHOLE BODY
1Departments of Internal Medicine and Pathology, Yale University School of Medicine, New Haven, and the Radiation Laboratory of the University of California, Berkeley.
The Journal of Experimental Medicine
|October 30, 2009
Summary
Neutron radiation exposure in mice causes effects similar to X-rays, with intestinal and lymphoid tissues being most sensitive. Workers handling neutrons require protective screening due to their higher biological destructive power compared to X-rays.
Area of Science:
- Radiation biology
- Radiobiology
- Medical physics
Background:
- Neutron radiation shares similarities with Roentgen (X-ray) irradiation in its biological effects.
- The gastrointestinal tract mucosa and lymphoid/hematopoietic tissues are identified as highly radiosensitive.
- Mortality mechanisms involve tissue destruction and enterogenous infections, with tissue destruction dominating acute, high-dose effects.
Purpose of the Study:
- To compare the biological effects of neutron irradiation with Roentgen irradiation.
- To identify the most radiosensitive tissues following whole-body neutron exposure.
- To establish safety guidelines for laboratory personnel working with neutron sources.
Main Methods:
- Whole-body irradiation of mice using neutron rays.
- Clinical, bacteriological, and anatomical assessments post-irradiation.
- Comparison of biological effects based on ionization levels measured by a thimble chamber.
Main Results:
- Neutron irradiation produced effects comparable to Roentgen irradiation.
- Small intestinal mucosa and lymphoid/hematopoietic tissues exhibited highest radiosensitivity.
- Neutrons demonstrated greater biological destructive potential per unit of ionization than X-rays.
Conclusions:
- Workers with neutron sources must implement protective screening measures.
- Recommended daily neutron dose for workers should be one-fourth of the accepted X-ray tolerance dose.
- Further research is needed to understand long-term effects of low-dose neutron exposure and therapeutic applications.
Related Concept Videos
02:59Biological Effects of Radiation
All radioactive nuclides emit high-energy particles or electromagnetic waves. When this radiation encounters living cells, it can cause heating, break chemical bonds, or ionize molecules. The most serious biological damage results when these radioactive emissions fragment or ionize molecules. For example, α and β particles emitted from nuclear decay reactions possess much higher energies than ordinary chemical bond energies. When these particles strike and penetrate matter, they produce ions...
01:24X-ray Imaging
German physicist Wilhelm Röntgen (1845–1923) was experimenting with electrical current when he discovered that a mysterious and invisible "ray" would pass through his flesh but leave an outline of his bones on a screen coated with a metal compound. In 1895, Röntgen made the first durable record of the internal parts of a living human: an "X-ray" image (as it came to be called) of his wife’s hand. Scientists worldwide quickly began their own experiments with X-rays, and by 1900, X-ray was widely...
03:23Types of Radioactivity
The most common types of radioactivity are α decay, β decay, γ decay, neutron emission, and electron capture.
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay:
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay:
01:28Isotopes and Radioisotopes
In the early 1900s, English chemist Frederick Soddy realized that an element could have atoms with different masses that were chemically indistinguishable. These different types are called isotopes — atoms of the same element that differ in mass. Isotopes differ in mass because they have different numbers of neutrons but are chemically identical because they have the same number of protons. Soddy was awarded the Nobel Prize in Chemistry in 1921 for this discovery.
An isotope containing more...
An isotope containing more...
01:35Mutations
Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations can be characterized in a number of different ways: whether and how they alter the amino acid sequence of the protein, whether they occur over a small or large area of DNA, and whether they occur in somatic cells or germline cells.
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
03:18Radioactivity and Nuclear Equations
Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The nucleus of an atom is composed of protons and, except for hydrogen, neutrons. The number of protons in the nucleus is called the atomic number (Z) of the element, and the sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are isotopes of the same element.
A nuclide of an element has a specific number of protons and...
A nuclide of an element has a specific number of protons and...