Effects of nuclear explosions on human health

• Initial stage—the first 1–9 weeks, in which are the greatest number of deaths, with 90% due to thermal injury and/or blast effects and 10% due to super-lethal radiation exposure.
• Intermediate stage—from 10 to 12 weeks. The deaths in this period are from
  LD50
• Late period—lasting from 13 to 20 weeks. This period has some improvement in survivors' condition.
• Delayed period—from 20+ weeks. Characterized by numerous complications, mostly related to healing of thermal and mechanical injuries, and if the individual was exposed to a few hundred to a thousand
  millisievert exposure has been shown to statistically begin increasing a person's chance of dying of cancer sometime in their lifetime over the normal unexposed rate of c. 25%, in the long term, a heightened rate of cancer, proportional to the dose received, would begin to be observed after c. 5+ years, with lesser problems, such as eye cataracts
  , and other more minor effects in other organs and tissue also being observed over the long term.

The main causes of death and disablement in this state are thermal burns and the failure of structures resulting from the blast effect. Injury from the pressure wave is minimal in contrast because the human body can survive up to 2 bar (30 psi) while most buildings can withstand only a 0.8 bar (12 psi) blast. Therefore, the fate of humans is closely related to the survival of the buildings around them.[7]

Fate within certain peak overpressure

• over 0.8 bar (12 psi) - 98% dead, 2% injured
• 0.3 - 0.8 bar (5-12 psi) - 50% dead, 40% injured, 10% safe
• 0.14 - 0.3 bar (2-5 psi) - 5% dead, 45% injured, 50% safe^[7]

Types of radioactive exposure after a nuclear attack

In a nuclear explosion, the human body can experience varying types of radiation. This radiation can be classified into two groups: initial radiation and residual radiation. Initial radiation is emitted during the initial explosion, which releases short-term

• Thermal burns from infrared heat radiation, these would be the most common burn type experienced by people.
• If people come in direct contact with
  beta burns from shallow ionizing beta radiation will be experienced, the largest particles (visible to the naked eye) in local fallout would be likely to have very high radioactivity because they would be deposited so soon after detonation; this fraction of the total fallout is called the prompt or local fallout fraction. It is likely that one such particle upon the skin would be able to cause a localized beta burn. This local fallout, termed Bikini snow after the Pacific island weapon tests,^[9] was experienced by the crew on the deck of the Lucky Dragon fishing ship following the explosion of the 15 megaton Shrimp device in the Castle Bravo event. However, these particular decay particles (beta particles
  ) are very weakly penetrating and have a short range, requiring almost direct contact between fallout and personnel to be harmful.
• Rarer still would be personnel who experience radiation burns from highly penetrating gamma radiation. This would likely cause deep gamma penetration within the body, which would result in uniform whole body irradiation rather than only a surface burn. In cases of whole body gamma irradiation (c. 10 Gy) due to accidents involving medical product irradiators, some of the human subjects have developed injuries to their skin between the time of irradiation and death.

In the picture above, the normal clothing (a

Radiation poisoning, also called "radiation sickness" or a "creeping dose", is a form of damage to organ tissue due to excessive exposure to

The "prodromal syndrome" is not a diagnosis, but the technical term used by health professionals to describe a specific group of symptoms that may precede the onset of an illness. For example, a fever is "prodromal" to measles, which means that a fever may be a risk factor for developing this illness. The prodromal symptoms for radiation poisoning can include symptoms such as feelings of nausea, increased thirst, loss of appetite, discomfort, fever, and diarrhea.[11]

Bone marrow death

In 24 hours:[10]

• vomiting
• diarrhea

These will usually abate after 6–7 days.

Within 3–4 weeks there is a period of extreme illness.^[10]

• severe bloody diarrhea, indicating intestinal disorders causing fluid imbalance
• extensive internal bleeding
• sepsis infections

The peak incidence of acute BM death corresponds to the 30-day nadir in blood cell numbers. The number of deaths then falls progressively until it reaches 0 at 60 days after irradiation. The amount of radiation greatly affects the probability of death. For example, over the range of 2 to 6 Gray the probability of death in untreated adults goes from about 1% to 99%, but these figures are for healthy adults. Therefore, results may differ, because of the thermal and mechanical injuries and infectious conditions.^[10]

Gastrointestinal death

Gastrointestinal death is caused by a dose of radiation between 10 and 50 Gray. Whole body doses cause damage to

The symptoms of gastrointestinal death are:[10]

• gastrointestinal pain
• anorexia
• nausea
• vomiting
• diarrhea

Central nervous system death

Central nervous system death is the main cause of death in 24–48 hours among those exposed to 50 Gray.^[10]

The symptoms are:^[10]

• vomiting
• nausea
• diarrhea
• drowsiness
• lethargy
• tremors
• delirium
• frequent seizures
• convulsions
• heat prostration
• coma
• respiratory failure
• death

Short-term effects (6–8 weeks)

Skin

The skin is susceptible to beta-emitting radioactive fallout. The principal site of damage is the germinal layer, and often the initial response is erythema (reddening) due to blood vessels congestion and edema. Erythema lasting more than 10 days occurs in 50% of people exposed to 5-6 Gray.^[10]

Other effects with exposure include:^[10]

• 2–3 Gray—temporary hair loss
• 7 Gray—permanent
  epilation
  occurs
• 10 Gray—itching and flaking occurs
• 10–20 Gray—weeping blistering and ulceration will occur

Lungs

The

Radiation pneumonitis is characterized by:^[10]

• Loss of epithelial cells
• Edema
• Inflammation
• Occlusions of airways, air sacs and blood vessels
• Fibrosis

Ovaries

A single dose of 1–2 Gray will cause temporary damage and suppress menstruation for periods up to 3 years; a dose of 4 Gray will cause permanent sterility.^[10]

Testicles

A dose of 0.1 Gray will cause low sperm counts for up to a year; 2.5 Gray will cause sterility for 2 to 3 years or more. 4 Gray will cause permanent sterility.^[10]

Long-term effects

Cataract induction

The timespan for developing this symptom ranges from 6 months to 30 years to develop but the median time for developing them is 2–3 years.^[10]

• 2 Gray of gamma rays cause opacities in a few percent
• 6-7 Gray can seriously impair vision and cause
  cataracts

Cancer induction

Cancer induction is the most significant long-term risk of exposure to a nuclear bomb. Approximately 1 out of every 80 people exposed to 1 Gray will die from cancer, in addition to the normal rate of 20 out of 80. About 1 in 40 people will get cancer, in addition to the typical rates of 16-20 out of 40. Different types of cancer take different times for them to appear:^[10]

• 2 years for leukemia to appear
• 20 or more years for skin cancer or lung cancer

In utero effects on human development

A 1 Gy dose of radiation will cause between 0 and 20 extra cases of perinatal mortality, per 1,000 births and 0-20 cases per 1000 births of severe mental sub-normality. A 0.05 Gy dose will increase death due to cancer 10 fold, from the normal 0.5 per 1000 birth rate to a rate of 5 per 1,000.^{[citation needed]} An antenatal dose of 1 Gy in the first trimester causes the lifetime risk of fatal cancer sometime in the child's life to increase from c. 25% in non-exposed humans to 100% in the first trimester after exposure.^[10]

Transgenerational genetic damage

Exposure to even relatively low doses of radiation generates genetic damage in the progeny of irradiated rodents. This damage can accumulate over several generations.^[12] No statistically demonstrable increase of congenital malformations was found among the later conceived children born to survivors of the Nuclear weapons at Hiroshima and Nagasaki.^[13][14][15] The surviving women of Hiroshima and Nagasaki, that could conceive, who were exposed to substantial amounts of radiation, went on and had children with no higher incidence of abnormalities than the Japanese average.^[16][17]

Infectious diseases resulting from nuclear attack

It was assumed in the 1983 book Medical Consequences of Radiation Following a Global Nuclear War that, although not caused by radiation, one of the long-term effects of a nuclear war would be a massive increase in

• Dysentery
• Typhoid
• Infectious hepatitis
• Salmonellosis
• Cholera
• Meningococcal meningitis
• Tuberculosis
• Diphtheria
• Whooping cough
• Polio
• Pneumonia

There would be billions of disease carrying

See also

Wikimedia Commons has media related to Radiation health effects.

• Blast shelter
• Fallout shelter
• Textbook of Military Medicine

Notes