Acute Radiation Syndrome Overview

The initial stage of ARS where symptoms start within hours after a whole-body radiation dose of 1 Gy or more. Symptoms are dose-related, with higher doses leading to more severe symptoms.

The dose of radiation required to kill 50% of an exposed population within 60 days.

The dose of radiation required to kill 50% of an exposed population.

The time period after exposure to radiation where no visible symptoms are present. Recovery or lethal effects begin during this time.

Radiation responses that increase in severity as the radiation dose increases. They usually have a threshold dose below which they do not occur.

The period following the latent period when symptoms become visible, impacting the blood-forming, gastrointestinal, and nervous systems.

A biological process where cells, after exposure to sublethal doses of radiation, repair and recover their functionality. Surviving cells repopulate, restoring organ function.

The syndrome that occurs when a large amount of ionizing radiation is absorbed by the body over a short period.

The extent of functional damage to an organ determines its potential for recovery. Oxygenated cells are more severely damaged by radiation than hypoxic cells but have better repair mechanisms.

Radiation damage can accumulate over time. About 10% of the damage is permanent, while the rest can be repaired through cell repair and reproduction.

ARS (Acute Radiation Syndrome) is a set of symptoms caused by high-level radiation exposure. Three main syndromes exist based on the radiation dose: hematopoietic, gastrointestinal, and cerebrovascular.

Hematopoietic syndrome is characterized by damage to the bone marrow, leading to a decrease in blood cells like red cells, white cells, and platelets.

The hematopoietic system is the most sensitive vital organ system to radiation damage. It is responsible for producing blood cells, including red blood cells for oxygen transport, white blood cells for fighting infection, and platelets for clotting.

Symptoms of hematopoietic syndrome include a decrease in white blood cells, making the body more susceptible to infection. A decrease in platelets leads to increased risk of bleeding.

The prodromal syndrome is the initial set of mild symptoms that appear soon after radiation exposure and can last for several days. These symptoms are often nausea, vomiting, and fatigue.

The survival time for individuals with hematopoietic syndrome depends on the radiation dose received. Higher doses lead to shorter survival times due to severe bone marrow damage and complications like infections and bleeding.

A range of radiation doses that primarily affects the bone marrow and leads to death within 6-8 weeks.

A period of apparent well-being after the prodromal stage, where the bone marrow is undergoing damage, though the individual may feel healthy.

A dose between 1 to 2 Gy, where bone marrow cells can repopulate, leading to potential recovery.

The time taken for bone marrow to recover after non-lethal radiation exposure, ranging from 3 weeks to 6 months.

The process of bone marrow cells regaining their function and replenishing after radiation exposure.

The dose range that causes death due to the destruction of bone marrow cells, where death occurs sooner with higher doses.

The Gastrointestinal Syndrome, a severe radiation sickness, affects the digestive system and occurs at a threshold dose of approximately 6 Gy (600 rads).

A prodromal stage, characterized by nausea and vomiting, occurs a few hours after radiation exposure, followed by a latent period (up to 5 days) where symptoms disappear.

The most severe damage happens to the small intestine, specifically the epithelial cells lining it.

The breakdown of epithelial cells leaves the body vulnerable to infections (mostly from gut bacteria), dehydration, and severe diarrhea.

The Gastrointestinal Syndrome results in death within 3 to 10 days after radiation exposure due to severe infection, fluid loss, and electrolyte imbalance.

Some epithelial cells regenerate after radiation exposure, but their regeneration is often not enough to save the organism from death.

The LD50/60 for Gastrointestinal Syndrome is approximately 2.5 to 5 Gy (250 to 500 rads).

The Chernobyl workers and firefighters are examples of individuals who succumbed to the gastrointestinal syndrome after radiation exposure.

The initial stage of ARS where symptoms start within a few hours after exposure. It features nausea, vomiting, diarrhea, and abdominal cramps. The severity of symptoms is linked to the radiation dose.

A period following the prodromal stage where the body appears to be recovering. However, cell damage is occurring, and the body is preparing for the manifest illness stage.

The stage where the full effects of ARS become evident, with severe diarrhea, fever, dehydration, and electrolyte imbalance. It's characterized by a high risk of death due to complications.

A potentially fatal condition resulting from high doses of ionizing radiation to the central nervous system and cardiovascular system. Death can occur within a few hours to 2-3 days.

The initial stage of Cerebrovascular Syndrome where early symptoms appear, related to nervous system dysfunction.

A period following the prodromal stage of Cerebrovascular Syndrome where symptoms may lessen or disappear temporarily.

The stage where the full effects of Cerebrovascular Syndrome become severe. Existing symptoms worsen, and new ones emerge, leading to a high risk of death.

The brain's intricate network of blood vessels, responsible for delivering oxygen and nutrients while removing waste products.

Tiny blood vessels that allow for exchange of nutrients and waste between blood and brain tissue.

The pressure exerted by fluids within the skull, which can be increased by excessive fluid buildup.

The protective barrier that restricts the passage of most substances from the bloodstream into the brain.

Tight junctions between brain capillaries that seal gaps, preventing substances from entering the brain easily.