Monday, April 18, 2011

Low and Long

So, we know that exposing to enormously high radiation all at once or having accumulated over 100 millisieverts will increase the cancer risk. But what would happen if we were exposed to low radiation for a long period?

Nikkei newspaper of April 17 showed the above graph. The title is “The risk of cancer death based on an epidemiological research in the high radiation area in India.”  I googled some erroneous spelling, but luckily, I found the following.

On the graph, the left vertical line shows risk, and in this case, the risk is set to 1. The bottom horizontal line shows the value in millisieverts. The longer they are exposed with low level of radiation, the risk is going down. Isn’t that interesting? I heard some part of Brazil and Iran has high background radiation, so I guess the situation must be similar. In the above web article, I found the words, terrestrial gamma radiation. Terrestrial sounds mysterious. It reminds of Ashok’s blog on Paspermia and Pansmeria. What we have under our lands are scary like faults, plates, and radioactive mineral but also fascinating.

According to Nikkei, in Karunagappally, Kerala, India, radioactive minerals are scattered in the area, and the average radiation there is 5 to 10 times more than the world average. The residents are exposed to the natural radiation of 10 to 20 millisieverts a year. In 2009, a study on 70,000 residents was conducted. The result was even the people who had accumulated over 600 millisieverts showed no evidence  in the difference on risk when compared with a control group. For the same amount of radiation, if our exposure took a long period, then the effect on living thing would be smaller.

In recent weeks, I’ve gained quite many readers from Ukraine. I’m glad to see my blog statistic map turn green there. Now I know exactly where Ukraine is in the world map. I just want to say that I hear often Japanese scientists refer to what they’ve learned from the Chernobyl accident. Because the experts were able to accomplish many studies in Ukraine, the Japanese government quickly notified us about radiation when rained and the danger of pipe water for babies. They distributed bottled water to affected families. I appreciate the knowledge.


keiko amano said...

I received this email from K.

I found your story on background radiation interesting.Especially about
the one done in India that supposely shows with a slightly elevated
radiation count it lowers the cancer rate.I guess the Indian's don't
consider radon gas as back ground radiation. Because study have shown
being exposed to radon gas increases the cancer rate.Although I don't
know at what radiation level it becomes dangerous.

I think no matter what kind of scientific data you show, pertaining to
the safety of low level radiation you will never convince the average
person from his natural fear of radiation.

keiko amano said...
This comment has been removed by the author.
keiko amano said...


Thank you for your comment.

Many studies have been conducted throughout the world to arrive at scientific data. We can't trust just because people believe or not, but we can trust good data. I think most of us including me are average, and we all need more education especially on what we fear. Don't you agree? There is so much to learn, and I enjoy learning and writing. To write means to think.

About the Kerala study, it must be much more complex. Maybe, you can find more info. on the web. But, what amazed me is the ability for humans' cells to keep recovering.

A friend of mine told me that he met a man who was exposed to the Hiroshima radiation. Because of it, the man didn't marry out of his fear of having children with health problems. The friend said the man looked very young with excellent skin (he kept saying this, and it almost made me think because of the radiation, but I doubt it.) The man married when he was 56, and has healthy children. There is so much we don't know, but I do know many Hiroshima people suffered from prejudice, and prejudice usually come from ignorance.