Radiation sickness

What is radiation sickness?

Natural background radiation, known as non-ionizing radiation, such as light, natural radio waves and microwaves generally causes only low levels of damage which can be repaired by the body. However, when the body is exposed to unnaturally high levels of radiation, usually from medical testing and therapy, industrial and manufacturing processes or accidents, and from nuclear weaponry, it cannot combat the damage caused.

There is great individual variation in how people respond to radiation and the process is not fully understood.Among the cells that are most sensitive to radiation are those that have a high turnover such as cells which line the intestine (crypt cells), white blood cells that fight infection and the cells that make red and white blood cells. The acute impact on these cells leads to the classic early symptoms of radiation sickness. For instance, damage to the intestine cells stimulates nausea, vomiting and dehydration. Chronic radiation exposure leads to an increased risk of cancer and premature ageing.

Radiation penetrates the body and is wholly or partially absorbed by soft and hard tissue.

Radioactive fallout in the form of particulate matter can be swallowed or breathed in.

Causes and risk factors

Exposure to radiation can cause devastating damage to the immune system and to the tissues of the body. The effects are known as radiation sickness or syndrome. Radiation can also cause little understood changes to the body's genes, which can be manifested through the development of diseases such as cancer later in life, and possibly as birth defects in future generations.

Symptoms

There are many symptoms of radiation sickness, and their severity varies greatly depending on the dosage. The initial symptoms include:

• Nausea
• Vomiting
• Diarrhoea
• Fatigue

These symptoms may be followed by:

• Headache
• Shortness of breat
• Rapid heartbeat
• Inflammation of the mouth and throat
• Worsening of tooth or gum disease
• Hair loss
• Dry cough
• Heart inflammation with chest pain
• Burning
• Permanent skin darkening
• Bleeding spots anywhere under the skin
• Haemorrhage
• Anaemia

In severe cases, where the radiation exposure has been extreme - approximately 10 gray (gray are measures of radiation) or more - death may occur within two to four weeks. Those who survive six weeks after the receipt of a single large dose of radiation to the whole body may generally be expected to recover

Treatment and prevention

There is no specific treatment once exposure has occurred but management is generally supportive whilst the body recovers from the damage done - anti-nausea drugs and painkillers can be used to relieve symptoms of radiation sickness. Antibiotics may also be needed to fight off secondary infection.

Blood transfusions may be necessary for patients suffering from anaemia.

What is the long-term health impact?

Radiation-related illnesses tend to show themselves about 10 to 15 years after a radiation disaster. The body's endocrine, or hormone-secreting, glands appear to be particularly sensitive to radiation.

It is now widely accepted that the Chernobyl nuclear disaster has led to a massive increase in thyroid cancers in the three countries most affected. Already, 680 cases of thyroid cancer have been recorded in Belarus, Russia and Ukraine. Belarus has shown a 100-fold increase, from 0.3 per million in 1981-85 to 30.6 per million in 1991-94.

Unicef has noted significant increases in many types of health disorders in Belarus since the disaster. For example, problems of the nervous and sensory organs have increased by 43%; disorders of the digestive organs by 28%; and disorders