After the atomic bombing of Hiroshima in August 1945, the most common diseases among survivors were primarily related to the intense radiation exposure and the immediate physical trauma caused by the blast. These health effects can be broadly categorized into acute radiation syndrome, long-term cancer risks, and various other radiation-induced conditions.
**Acute Radiation Syndrome (ARS)** was the most immediate and severe health condition experienced by many survivors. ARS occurs when a person is exposed to a high dose of ionizing radiation in a short period. Symptoms typically began within hours and included nausea, vomiting, diarrhea, and loss of appetite. In the days and weeks following exposure, survivors could experience a temporary improvement, but then more serious symptoms would develop, such as severe infections, bleeding, and neurological problems. ARS is divided into subtypes depending on the radiation dose and affected body systems: bone marrow syndrome (leading to decreased blood cell production), gastrointestinal syndrome (causing severe digestive tract damage), and neurovascular syndrome (affecting the nervous system at extremely high doses). Many who suffered from ARS died within weeks or months due to infections or organ failure caused by the radiation damage to rapidly dividing cells in the body[3].
Beyond the acute phase, survivors faced **long-term health effects**, especially an increased risk of various cancers. Radiation exposure damaged DNA in cells, which could lead to mutations and the development of cancers years or decades later. The most common cancers observed included leukemia, particularly acute myeloid leukemia, which appeared relatively soon after exposure, and solid tumors such as lung, breast, thyroid, and stomach cancers, which developed over a longer period. However, recent research has shown that the overall long-term cancer death rate among Hiroshima survivors was lower than initially feared, with less than 1% expected to die from radiation-induced cancers. This suggests a complex relationship between radiation dose, individual susceptibility, and cancer risk[1].
In addition to cancers, survivors experienced **genetic mutations** and other chronic health problems. Some children born to survivors showed increased rates of birth defects and developmental issues, although the extent of hereditary effects was less severe than once feared. Survivors also suffered from **physical deformities and growth impairments**, likely due to radiation damage during fetal development or early childhood[2].
Other common health issues included **chronic radiation dermatitis**, where the skin showed long-lasting damage such as scarring and ulceration, and **cataracts**, a clouding of the eye lens caused by radiation exposure. Psychological trauma and social stigma also affected survivors, contributing to mental health problems and difficulties in social integration.
Environmental contamination from residual radiation initially affected the soil, water, and local wildlife, but the most harmful radiation decayed rapidly within weeks after the bombing. Cleanup and decontamination efforts helped reduce environmental radiation levels, and today Hiroshima’s radiation levels are comparable to natural background levels, making the city safe for habitation[2].
In summary, the diseases most common after the Hiroshima bombing were acute radiation syndrome in the immediate aftermath, followed by increased risks of leukemia and solid cancers, genetic and developmental disorders, chronic skin and eye conditions, and psychological effects. The severity and variety of these diseases reflected the intense and complex impact of the atomic bomb’s radiation and blast effects on human health.