Radiation is energy released from unstable atoms. Humans are constantly exposed to both natural and human-made sources, found in the environment, food, water, and medical procedures. Exposure occurs when this energy enters the body, like during an X-ray. Contamination, however, means radioactive materials are present on or inside a person’s body. These can enter through swallowing, breathing, open wounds, or skin absorption. This article explores how the body interacts with radiation and methods to manage its effects.
The Body’s Natural Response to Radiation
The human body has mechanisms to manage radiation damage and eliminate radioactive substances. When radiation interacts with the body, it can cause cellular damage, which the body’s cells work to repair.
The body also naturally eliminates certain radioactive materials through excretory processes like urine, feces, sweat, and blood. This natural removal is slow, and its effectiveness depends on the type, quantity, and duration of exposure.
The concept of biological half-life describes the time for half of a radioactive substance to be naturally eliminated from the body. This differs from physical half-life, which is the time for half of the radioactive atoms to decay. For example, Cesium-137 has a physical half-life of 30 years, but its biological half-life in humans can range from 70 to 100 days. The effective half-life considers both physical decay and biological elimination, providing a more accurate picture of how long a substance remains active.
Medical Treatments for Internal Radioactive Contamination
Medical interventions address internal radioactive contamination by removing or blocking absorption of radioactive materials. These treatments are tailored to the substance and require medical supervision.
Potassium Iodide (KI)
KI is a medication for radioactive iodine (I-131). The thyroid gland absorbs iodine to produce hormones and cannot differentiate between stable and radioactive iodine. KI saturates the thyroid with stable iodine, preventing radioactive iodine uptake and protecting the gland. It is most effective if administered shortly before or after exposure.
Prussian Blue
Prussian Blue (Radiogardase) accelerates the removal of radioactive cesium (Cs-137) and thallium. It binds to these elements in the intestines, forming a stable complex excreted through feces. Prussian Blue is not absorbed into the bloodstream, remaining in the gastrointestinal tract to prevent re-absorption. It can significantly reduce the biological half-life of these substances, such as cesium’s by approximately 43%.
Chelation Therapy
Chelation therapy uses chelating agents, like Diethylenetriamine Pentaacetate (DTPA), to bind to certain radioactive metals. DTPA is approved for plutonium, americium, and curium contamination. These agents form stable complexes with the metals, which are then excreted, primarily through urine. Calcium-DTPA (Ca-DTPA) and zinc-DTPA (Zn-DTPA) are available; Ca-DTPA is more effective if given within the first day. DTPA helps remove contaminants but does not repair existing radiation damage.
Diuretics
Diuretics, which increase fluid excretion, can play a minor role in flushing out some soluble radioactive substances. This approach has limited effectiveness for significant contaminations. Their primary utility is to support the body’s natural elimination processes, especially when the material is readily excreted through the kidneys.
Reducing Exposure and Preventing Uptake
While medical treatments focus on removing radioactive materials from inside the body, reducing initial exposure and preventing uptake are also important. These strategies aim to minimize the amount of radioactive material that enters the body in the first place, mitigating the overall impact of radiation.
Principles of Radiation Protection
Three principles for external exposure are time, distance, and shielding.
Minimizing time near a source directly reduces the dose.
Increasing distance significantly lowers exposure; radiation intensity decreases rapidly with distance. Doubling the distance can reduce exposure to one-fourth.
Shielding involves placing a barrier between a person and the source. Materials like lead, concrete, or water can absorb radiation depending on its type.
Decontamination
Immediate decontamination of skin and clothing prevents internal absorption and reduces external exposure. Removing outer clothing can eliminate up to 90% of radioactive material. Contaminated clothing should be carefully removed, placed in a sealed bag, and kept away from people and pets. Washing the body with soap and water, focusing on exposed areas, helps remove particles from the skin. Avoid scrubbing or scratching to prevent material from entering wounds.
Preventing Ingestion and Inhalation
Preventing ingestion and inhalation of radioactive substances is also important. This involves avoiding contaminated food, water, and air. In an emergency, staying indoors, closing windows and doors, and using respiratory protection if advised can help. Consuming bottled water and food from sealed containers is recommended. Covering cuts and abrasions when handling potentially contaminated items helps prevent material from entering the body through wounds.
Understanding Radiation Myths
Many misconceptions exist regarding radiation and body “detoxification.” It is important to distinguish between scientifically supported interventions and unproven claims. Popular ideas about specific foods, supplements, or “miracle cures” for radiation are not scientifically supported.
Effective radiation removal relies on specific, medically approved interventions or the body’s natural processes. Relying on unverified information can delay appropriate medical care and worsen outcomes. For instance, only pharmaceutical-grade Potassium Iodide, taken under medical guidance, effectively blocks radioactive iodine. Artistic Prussian blue dye is not suitable for treating contamination and can be harmful.