RIBs & BEIR P3

(P1 can be found here)

In this post, I'll shift from epidemiology to history in order to appreciate the LSS in the Big Picture.

The atomic bombings occurred in 1945.  We didn't discover DNA until 1953, though we had postulated how radiation might cause cancer.  We had directly observed cell effects and we had animal studies which showed radiation carcinogenesis.

The overall sense was that radiation caused cancer.  That's why we undertook the LSS!

But it would be years before any meaning epidemiological data could be derived from the LSS.

In the meantime, studies (of varying quality) were done on radiologists, radiation therapy patients, radium dial painters, etc.  These convinced us that radiation causes cancer.  Regulations up until then had been based on acute effects, but we suspected carcinogenesis might be at play and this led to more restrictive regulations.  Animal studies continued to support this view, too.

Historically, looking back in time from 1945...there wasn't a better study to be found.

Looking forward in time from 1945 until today...there isn't a better study to be found.

But there are some more insights to be gained:

We have radon studies.  These were first carried out on uranium miners and then on the general public.  Excess cancers under LNT conditions are clearly seen throughout these real life situations.

Fukushima.  This only happened this year.  We won't learn much from it anytime soon.

Chernobyl.  This occurred in 1986.  That's time to give epidemiology the statistical power to start seeing the earliest cancers (thyroid & leukemia).  It's not enough time for other solid tumors.  And guess what?

All the evidence shows that LNT is the best (regardless of its imperfections) model describing dose versus carcinogenesis.  (This view is supported by molecular biology as well.)

Note that the Chernobyl exposures are primarily from internally deposited radioactivity, not external whole body radiation.


Next::  The LSS (in a little, but not too much detail)