Interesting Radiation Dose chart

[mdbee]

Gives a good perspective on the hysteria from the news shows.

http://xkcd.com/radiation/

[SlowButSteady]

Your link fails to take the mutagenic effects of radiation into account. Since the relationship between radiation and cancer has NO MINIMUM DOSE any elevation in radiation exposure will elevate the probability of developing cancer. Add to that the effects of bioaccumulation and bioconcentration of radioisotopes and the "hysteria" becomes a bit more understandable.

The total number killed as a direct result of acute radiation sickness from the Chernobyl accident was in the dozens, however, the number of additional cancer cases involving people who were in the immediate area around Chernobyl and in the fallout zone stretching across much of Eastern and Northern Europe is in the THOUSANDS. The eventual additional mortality attributable to that accident has been estimated to be in the hundreds of thousands, as increased cancer rates will likely continue to be seen for decades, perhaps generations. While the Fukushima meltdowns and fires will probably not result in nearly the radiation releases seen at Chernobyl, the overall effects of the latter demonstrate the fallacy of simply looking at radiation as it relates to acute sickness.

[rmeador]

The orange portion of the chart contains a dosage labeled "lowest one-year dose clearly linked to increase cancer risk". This implies doses lower than that are not clearly linked to an increase in cancer risk. If you know of credible research that contradicts this, send it in to Randall (xkcd) and I'm sure he'll update the chart.

[SlowButSteady]

Radiation causes cancer by inducing point mutations in DNA. The higher the dose of radiation, the higher the probability of a cancer-causing mutation. This is true at "background" radiation levels, just with a lower probability of inducing cancer. Raise the radiation level, you raise the mutation rate, and you raise the incidence of cancer. There is no "threshold", unless you consider zero.

(If you know of credible research contradicting this, you might want to contact the author(s) of every modern Introductory Biology textbook.)

[obarut]

It seems having 2 CT scan in a year is extremely dangerous!

[WouldaShoulda]

If you think that's bad, try standing in the sun!!

[obarut]

As far as I know total dose that can be get from background radiation including sun is about 0.03 Sievert/year which below allowable dose of 0.05 Sievert/year for a healthy person.

[rmeador]

Your body is quite capable of repairing the damage to your DNA caused by small amounts of radiation. This is why small amounts of radiation do not correlate well with increased cancer risk. It's only after you get above the threshold that your body can repair that you run into statistically significant increases in cancer risk.

Here's some sources for you:
Radiation and Risk
DNA repair - Wikipedia, the free encyclopedia

[SlowButSteady]

Originally Posted by rmeador

Your body is quite capable of repairing the damage to your DNA caused by small amounts of radiation. This is why small amounts of radiation do not correlate well with increased cancer risk. It's only after you get above the threshold that your body can repair that you run into statistically significant increases in cancer risk.

Here's some sources for you:
Radiation and Risk
DNA repair - Wikipedia, the free encyclopedia

[EDIT-JRP]

I'm not some Wikipedia-dependent troll. I've worked as a biologist for almost 30 years now. While cell biology and genetic repair mechanisms are not directly related to my research, I sure as hell didn't just learn about them by surfing the Internet and stumbling across a Wiki page.

DNA repair mechanisms ARE NOT perfect, they only lower the probability of a cell lineage having a heritable mutation relative to the initial probability of damage. In other words, there is always a non-trivial (non-zero) probability of heritable damage, and that probability increases with radiation exposure, even after DNA repair mechanisms have worked their mojo. In fact the proteins involved in DNA repair are also susceptible to radiation damage. There is always a tradeoff between the benefit of a particular radiation exposure (diagnosing a broken arm, finding an embolism, treating a malignancy, et cetera) and the increased probability of doing harm. THERE IS NO THRESHOLD for radiation exposure below which there is no increased probability of doing harm.

[mdbee]

Wonder why things seem to get out of hand around here? I just posted the chart because I found it interesting to see a comparison of different sources and amounts of radiation.

Was the chart controversial? Hey, it wasn't from Wiki or Fox News!