Clarifying the facts about Internal and External Emitters of Ionising Radiation

Fukushima: Think Low Level Radiation Is Harmless? Think Again… UKIAH BLOG  In Around the web on August 25, 2013Time to combat radiation threat From WASHINGTON’S BLOG “…..Moreover, radioactive particles which end up inside of our lungs or gastrointestinal track, as opposed to radiation which comes to us from outside of our skin are much more dangerous than general exposures to radiation.

The National Research Council’s Committee to Assess the Scientific Information for the Radiation Exposure Screening and Education Program explains:

Radioactivity generates radiation by emitting particles. Radioactive materials outside the the body are called external emitters, and radioactive materials located within the body are called internal emitters.

Internal emitters are much more dangerous than external emitters. Specifically, one is only exposed to radiation as long as he or she is near the external emitter.

For example, when you get an x-ray, an external emitter is turned on for an instant, and then switched back off.

But internal emitters steadily and continuously emit radiation for as long as the particle remains radioactive, or until the person dies – whichever occurs first. As such, they are much more dangerous.

As the head of a Tokyo-area medical clinic – Dr. Junro Fuse, Internist and head of Kosugi Medical Clinic – said:

Risk from internal exposure is 200-600 times greater than risk from external exposure.

See thisthis, this and this.

By way of analogy, external emitters are like dodgeballs being thrown at you. If you get hit, it might hurt. But it’s unlikely you’ll get hit again in the same spot.

Internal emitters – on the other hand – are like a black belt martial artist moving in really close and hammering you again and again and again in the exact same spot. That can do realdamage.

http://ukiahcommunityblog.wordpress.com/2013/08/25/fukushima-think-low-level-radiation-is-harmless-think-again/#comments

 

 

There are few natural high-dose internal emitters. Bananas, brazil nuts and some other foods contain radioactive potassium-40, but in extremely low doses. And – as explained above – our bodies have adapted to handle this type of radiation.

True, some parts of the country are at higher risk of exposure to naturally-occurring radium than others.

But the cesium which was scattered all over the place by above-ground nuclear tests and the Chernobyl and Fukushima accidents has a much longer half life, and can easily contaminate food and water supplies. As the New York Times notes:

Over the long term, the big threat to human health is cesium-137, which has a half-life of 30 years.

At that rate of disintegration, John Emsley wrote in “Nature’s Building Blocks” (Oxford, 2001), “it takes over 200 years to reduce it to 1 percent of its former level.”

It is cesium-137 that still contaminates much of the land in Ukraine around the Chernobyl reactor.

***

Cesium-137 mixes easily with water and is chemically similar to potassium. It thus mimics how potassium gets metabolized in the body and can enter through many foods, including milk.

As the EPA notes in a discussion entitled ” What can I do to protect myself and my family from cesium-137?”:

Cesium-137 that is dispersed in the environment, like that from atmospheric testing, is impossible to avoid.

Radioactive iodine can also become a potent internal emitter. As the Times notes:

Iodine-131 has a half-life of eight days and is quite dangerous to human health. If absorbed through contaminated food, especially milk and milk products, it will accumulate in the thyroid and cause cancer.

(In addition to spewing massive amounts of radioactive iodine 131, Fukushima also pumped out huge amounts of radioactive iodine 129 – which has a half-life of 15.7 million years. Fukushima has also dumped up to 900 trillion becquerels of radioactive strontium-90 – which is a powerful internal emitter which mimics calcium and collects in our bones – into the ocean.).

The bottom line is that there is some naturally-occurring background radiation, which can – at times – pose a health hazard (especially in parts of the country with high levels of radioactive radon or radium).

But cesium-137 and radioactive iodine – the two main radioactive substances being spewed by the leaking Japanese nuclear plants – are not naturally-occurring substances, and can become powerful internal emitters which can cause tremendous damage to the health of people who are unfortunate enough to breathe in even a particle of the substances, or ingest them in food or water.

Unlike low-levels of radioactive potassium found in bananas – which our bodies have adapted to over many years – cesium-137 and iodine 131 are brand new, extremely dangerous substances.

And unlike naturally-occurring internal emitters like radon and radium – whose distribution is largely concentrated in certain areas of the country – radioactive cesium and iodine, as well as strontium and other dangerous radionuclides, are being distributed globally through weapons testing and nuclear accidents.

http://ukiahcommunityblog.wordpress.com/2013/08/25/fukushima-think-low-level-radiation-is-harmless-think-again/#comments

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