Some people develop leukemia after radiation exposure because radiation can damage the DNA in blood-forming cells within the bone marrow, leading to mutations that disrupt normal cell growth and function. This damage can cause the bone marrow to produce abnormal white blood cells uncontrollably, which is the hallmark of leukemia.
Radiation, especially ionizing radiation like X-rays or gamma rays, has enough energy to break chemical bonds in DNA molecules. When DNA is damaged, cells normally try to repair it, but sometimes the repair is faulty or incomplete. This can result in mutations—permanent changes in the DNA sequence—that affect genes controlling cell division and death. If these mutations occur in hematopoietic stem cells (the cells in bone marrow that produce blood cells), they can lead to the development of leukemia by allowing abnormal cells to multiply unchecked.
Not everyone exposed to radiation develops leukemia because several factors influence this risk:
– **Dose and duration of radiation exposure:** Higher doses and prolonged exposure increase the chance of DNA damage and mutation accumulation. For example, survivors of atomic bombings or patients receiving high-dose radiotherapy have shown increased leukemia rates.
– **Individual genetic susceptibility:** Some people have inherited differences in their DNA repair mechanisms or other genetic factors that make them more vulnerable to radiation-induced mutations. For instance, conditions like Down syndrome or defects in DNA repair pathways increase leukemia risk.
– **Cellular environment and immune response:** The body’s ability to detect and eliminate abnormal cells varies among individuals. Radiation can also cause oxidative stress and inflammation, which may promote mutation and cancer development.
– **Age and developmental stage:** Children are more radiosensitive because their cells divide more rapidly and their bodies have a longer time to accumulate mutations leading to cancer.
Radiation-induced leukemia often arises years after exposure because it takes time for mutated cells to grow into a detectable cancer. The process involves multiple genetic hits—initial DNA damage followed by additional mutations that allow cancer cells to evade normal growth controls.
In summary, radiation can trigger leukemia by damaging DNA in bone marrow cells, but whether leukemia develops depends on the radiation dose, genetic factors, and the body’s ability to repair damage and control abnormal cells. This explains why only some people exposed to radiation go on to develop leukemia while others do not.
