Radiation hygiene

History of study and the dual nature of radiation

Ionizing radiation (IR) is a powerful physical factor that humans encounter both in everyday life and in the workplace. The late 19th and first half of the 20th century was a time of outstanding discoveries in this field. In 1895, Wilhelm Röntgen discovered X-rays, and a year later, Henri Becquerel discovered the natural radioactivity of uranium. Soon after, Pierre and Marie Curie described the properties of polonium and radium, Ernest Rutherford isolated alpha and beta particles, and in 1935, Irène and Frédéric Joliot-Curie discovered artificial radioactivity. All of these scientists were awarded Nobel Prizes.

However, the harnessing of radiation came at a high cost to humanity. Early researchers worked without protection, unaware of the hazards of radiation, which led to the deaths of many of them (including 13 Russian specialists). Today, it is clear that ionizing radiation plays a dual role. On the one hand, it has brought colossal benefits to physics, chemistry, biology, and medicine. On the other hand, it is a serious threat. The use of high technologies carries the risk of large-scale technological disasters, such as the chemical plant explosion in Bhopal, the loss of the Challenger astronauts, and the Chernobyl nuclear power plant accident.

Ecology and the prospects of energy

Despite this tragic experience, abandoning nuclear energy or space exploration is inexpedient. Fossil fuels (oil, coal, peat) are depleting rapidly and are not environmentally safe.

Burning fuel in boiler houses and thermal power plants causes enormous damage to nature:

• Colossal amounts of oxygen are consumed.
• Soot, dust, nitrogen oxides, and sulfur dioxide are released into the atmosphere.
• Hazardous radionuclides (uranium-238, thorium-232, radium-226, polonium-210, potassium-40) are emitted.

Notably, emissions from thermal power plants are still not properly monitored in terms of radiation factors. This is why most researchers believe that until the mass adoption of inexhaustible solar energy, there is no real and effective alternative to nuclear power plants.

Radiation safety

The main task of science in the era of the scientific and technological revolution is to create reliable protection systems. Radiation safety refers to a state in which both current and future generations of people are protected from the harmful effects of radiation. In the Russian Federation, the main regulatory document in this area is the Radiation Safety Standards (NRB-99).

The fundamental principle of radiation safety is health protection without creating unjustified obstacles to the beneficial use of IR in science, medicine, and the economy. Modern protection systems are quite effective during routine equipment operation. However, the risk of accidents is always present. This is due to the constant complication of technologies (it is impossible to calculate all failure scenarios) and the influence of the notorious human factor.

Biological effects of radiation

The initial stage of the damaging effect of radiation consists of the physical ionization of the medium and the absorption of energy by living cells. Depending on the dose (acute or chronic exposure), clinical medicine divides all consequences into two large groups:

1. Deterministic (threshold) effects Occur only when exposed to sufficiently high doses of radiation (there is a threshold below which the effect does not manifest). These include:

• Radiation sickness.
• Radiation burns of the skin and mucous membranes.
• Radiation cataract (opacity of the lens).
• Radiation-induced infertility.
• Severe fetal developmental anomalies.

2. Stochastic / probabilistic (non-threshold) effects Are associated with exposure to low doses of radiation, including those used in routine radiological medical procedures. There is no safety threshold: any dose increases the probability of pathology. They manifest as:

• Malignant tumors.
• Leukemias (blood cancer).
• Hereditary genetic diseases in offspring.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Mechanisms of medium ionization and features of cellular energy absorption.
• Clinical picture and stages of development of acute radiation sickness.
• Assessment of the risks of malignant neoplasms during medical procedures.
• Principles of applying the Radiation Safety Standards (NRB-99) in practice.
• Analysis of the role of the human factor in major radiation accidents.

Other topics in "Chapter 7. Basics of radiation hygiene"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.