What effects does radiation have on the human body?
In this article:
- Radiation Exposure Causes Somatic and Genetic Effects: Somatic effects impact the individual exposed—such as reduced white blood cell count—while genetic effects may affect future generations, though they are less understood and harder to measure.
- Severity Depends on Dose and Exposure Time: High doses over short periods can lead to acute radiation syndrome, while lower doses over time may cause long-term health issues, including cancer and organ damage.
- Blood Cells Are Early Indicators of Radiation Damage: Because blood cells are highly sensitive to ionizing radiation, changes in blood composition are often the first detectable signs, prompting routine blood tests for radiological workers.
- Radiation Effects Often Have a Latent Period: Symptoms may not appear immediately after exposure; effects can manifest days, months, or even years later, complicating diagnosis and long-term health monitoring.
- Understanding of Radiation Risks Has Evolved Over Decades: Advances in radiobiology have led to stricter dose limits and improved safety protocols, significantly reducing occupational exposure risks in industrial and medical settings.
The human body is constantly exposed to natural radiation (e.g. from space, the soil and buildings), also known as background radiation. All ionising radiation, whether electromagnetic (gamma-γ) or corpuscular (particles in the form of alpha-α or beta-β), and neu-
trons, are harmful to the human body. The unit “absorbed dose” (D) defines the effect of radiation on various substances. D is the absorbed dose in J/kg or Gray (Gy).
The biological damage done by the various types of ionising radiation, α, β, γ or fast neutrons, differs and depends on the quality factor (Q). The unit to which the damage quality factor is applied is the equivalent dose H. The equivalent dose is the product of absorbed dose (D) and quality factor (Q), so the equivalent dose is calculated as H = D x Q [Sv], (Sv = Sievert).
The Q factors for various types of radiation are indicated in table.
