What are the effects of Radiation?
Contrasting media reports abound regarding the dangers occurring at the Fukushima nuclear facility in Japan. The reports have triggered uncertainty, concern and even panic among members of the general public in Japan and around the world.
Workers in Japan have been bravely battling to save the facility from a disastrous meltdown, exposing their bodies to potentially dangerous and lethal doses of radiation. In this text, we attempt to explain what impact radiation may have on the human body.
Radiation takes place when the atomic nucleus of an unstable atom decays and starts releasing ionizing particles, known as ionizing radiation. When these particles come into contact with organic material, such as human tissue, they will damage them if levels are high enough, causing burns and cancer. Ionizing radiation can be fatal for humans.
REM (roentgen equivalent in man) – this is a unit we use to measure radiation dosage. We use this measurement to determine what levels of radiation are safe or dangerous for human tissue. It is the product of the absorbed dose in rads and a weighting factor (WR), which accounts for how effective the radiation is in causing biological damage.
A sudden, short dose of up to 50 rem will probably cause no problems, except for some blood changes. From 50 to 200 rem there may be illness, but fatalities are highly unlikely. A dose of between 200 and 1,000 will most likely cause serious illness – the nearer the 1,000 it is, the poorer the outlook for the human will be. Any dose over 1,000 will typically cause death.
When an atomic bomb explodes, as in Hiroshima and Nagasaki during WWII, people receive two doses of radiation: one during the explosion, and another from fallout. Fallout refers to the radioactive particles that float in the air after an explosion; they rise and then gradually descend to the ground. A dose of 100 rems will have probably cause some initial signs of radiation sickness, such as loss of white blood cells, nausea, vomiting, and headache. With a 300 rem dose you may lose hair temporarily – your nerve cells and those that line the digestive tract will be damaged. As the dose rises and more white blood cells are lost, the human’s immune system becomes seriously weakened – their ability to fight off infections is considerably reduced.
Exposure to radiation makes our bodies produce fewer blood clotting agents, called blood platelets, increasing our risk of internal bleeding. Any cut on the skin will take much longer to stop bleeding.
Experts say that approximately 50% of humans exposed to 450 rems will die, and 800 rems will kill virtually anyone. Death is inevitable and will occur from between two days to a couple of weeks.
Millisieverts per hour (mSv) – this is a measure used more commonly by the International Commission on Radiological Protection. For example:
* A gastrointestinal series X-ray investigation exposes the human to 14 mSv
* Recommended limit for volunteers averting a major nuclear escalation – 500 mSv (according to the International commission on Radiological Protection)
* Recommended limit for volunteers rescuing lives or preventing serious injuries – 1000 mSv (according to the International commission on Radiological Protection)
Below is a list of signs and symptoms likely to occur when a human is exposed to acute radiation (within one day), in mSv:
* 0 to 250 mSv – no damage
* 250 to 1,000 mSv. Some individuals may lose their appetites, experience nausea, and have some damage to the spleen, bone marrow and lymph nodes.
* 1000 to 3000 mSv – nausea is mild to severe, no appetite, considerably higher susceptibility to infections. Injury to the following will be more severe – spleen, lymph node and bone marrow. The patient will most likely recover, but this is not guaranteed.
* 3,000 to 6,000 mSv – nausea much more severe, loss of appetite, serious risk of infections, diarrhea, skin peels, sterility. If left untreated the person will die. There will also be hemorrhaging.
* 6,000 to 10,000 mSv – Same symptoms as above. Central nervous system becomes severely damaged. The person is not expected to survive.
* 10,000+ mSv – Incapacitation. Death. Those who do survive higher radiation doses have a considerably higher risk of developing some cancers, such as lung cancer, thyroid cancer, breast cancer, leukemia, and cancer of several organs.