Putting Radiation Dose in Perspective 4

[WoodyPE]

The so-called "standard" for food supply contamination is the banana equivalent dose (BED). Per Wikipedia:

http://en.wikipedia.org/wiki/Banana_equivalent_dose

"Many foods are naturally radioactive, and bananas are particularly so, due to the radioactive potassium-40, or 40K they contain. Bananas are radioactive enough to be detected by radiation sensors used to detect possible illegal smuggling of nuclear material at U.S. ports. A medium-sized banana contains about 450 mg of potassium. 40K makes up 0.0117% of this, or about 53 ?g, which produces 14 Becquerel (Bq), or 0.37 nCi of radiation."

"A radiation dose equivalent of 100 ?Sv (10 mrem, or 1,000 BED) increases an average adult human's risk of death by about one micromort – the same risk as eating 40 tablespoons of peanut butter, or of smoking 1.4 cigarettes."

Pardon the pun, but the BED of K40 is an apples to bananas comparison to other forms of radiation because the body is well-equipped to deal with K40 versus other elements.

The best I could tell, the spinach around Fukishima has 11 times more radiation than a banana on a weight basis. I had to make asumptions to get there because the reporting is so scant on measured scientific data.

 

[trottiey]

Something's wrong with some of those numbers, and the supporting references in that Wikipedia article aren't very authoritative. 100 ?Sv of radiation increases an average adult human's risk of death by about 4 micromorts, and that should equate to about a pack of cigarettes, not just 1.4 cigarette. I'm also skeptical about the comparison to peanut butter, though I have no better numbers to offer. At the very least, I found this source that says it's complicated:

http://www.ncbi.nlm.nih.gov/pmc/articles/.../pdf/envhper00353-0068.pdf

But yes, eating 1000 bananas or drinking 100 bottles of Gatorade would be roughly equivalent to 100 ?Sv.

From what I've read, drinking contaminated milk from the area daily for a year would give you an equivalent dose of around 10,000 ?Sv at current radioactivity levels. In practice, the contamination levels will rise as the incident progresses, and then fade as the radiation decays. Spinach rings in at 2,000 ?Sv per year of consumption given the same assumptions.

 

[rcchap]

Attached is a very informative comparison of radiation doses from many sources.