Escaping the LNT cult

[Al Capone Junior]

Could be nerd lab material but has profound implications, so posting here

https://paradigmsanddemographics.blogsp ... h.html?m=1

Professor Calabrese discusses LNT, threshold and hormesis models, history, fraud, recent successes, and his journey escaping from the LNT cult.

[Sciolus]

I have no idea what LNT is, have little desire to watch a video to find out, and everything else on that page makes me think "twunt!"

[KAJ]

It's the Linear no-threshold model Wikipedia

[Al Capone Junior]

It's the Linear no-threshold model Wikipedia

Sorry, I should have been more specific. Yes, linear no threshold.

The page is twunty but the interview was very interesting. Since I'm all for nuclear energy (especially molten salt / liquid fluoride thorium reactors) we really need LNT to NOT be the gold Standard. Because it's sh.t.

[Sciolus]

OK, as it happens I have a bit of interest in LNT. I haven't watched the video but I've skimmed a couple of Calabrese's papers.

I did nuclear safety work in the early 1990s, and controversy about LNT was old news then. The usual assumption was ¯\(°_o)/¯ I dunno lol. LNT is, in a sense, conservative, but that conservatism comes with an opportunity cost which in some circumstances may flip it into a bad assumption, and that has long been recognised.

What actually is Calabrese's argument? Is there new evidence, either an accumulation of poor-quality studies or a brilliant new technique for teasing out the tiny effects? AFAICT no, it's still as uncertain as ever.

Incidentally, it's not just ionising radiation. There are shedloads of things that seem to be harmful and which huge populations of people are exposed to at very low doses: pesticides, air pollutants, water pollutants, what have you. Often the evidence around the effects of low doses is weak. Sometimes a threshold is suspected, but it's usually LNT faut de mieux. Safety levels are usually set based on LNT and a "tolerable" level of risk. Got a better idea?

[bob sterman]

Incidentally, it's not just ionising radiation. There are shedloads of things that seem to be harmful and which huge populations of people are exposed to at very low doses: pesticides, air pollutants, water pollutants, what have you. Often the evidence around the effects of low doses is weak. Sometimes a threshold is suspected, but it's usually LNT faut de mieux. Safety levels are usually set based on LNT and a "tolerable" level of risk. Got a better idea?

Funny you should mention pesticides. The webpage showing the Calabrese interview belongs to Rich Kozlovich who says "I have served as a trustee on industry association boards representing pesticide and fertilizer applicators actively for almost 25 years."

[Little waster]

Incidentally, it's not just ionising radiation. There are shedloads of things that seem to be harmful and which huge populations of people are exposed to at very low doses: pesticides, air pollutants, water pollutants, what have you. Often the evidence around the effects of low doses is weak. Sometimes a threshold is suspected, but it's usually LNT faut de mieux. Safety levels are usually set based on LNT and a "tolerable" level of risk. Got a better idea?

Funny you should mention pesticides. The webpage showing the Calabrese interview belongs to Rich Kozlovich who says "I have served as a trustee on industry association boards representing pesticide and fertilizer applicators actively for almost 25 years."

Which presumably is not at all linked to:-

I also believe that to be green is to be irrational, misanthropic and morally defective. They are the barbarians at the gate we have to stand against. Our greatest worry is those within who support and facilitate their misanthropic goals.

As said earlier the rest of the website is a bit

Presumably the cause of Misanthropic Global Warming is people who know it is happening but don’t give a sh.t because they are c.nts.

[Allo V Psycho]

I used to work in the same Department as a radiation hormesis guy. The idea was that low doses of radiation would active the DNA repair mechanisms, which would then fix other errors which in themselves wouldn't have activated the repair mechanisms, hence you end up with better DNA all round. A bit like you spill something on the floor, so you mop the entire floor, when up to that point you had been ignoring the crud on it.

As I remember, even he wasn't THAT convinced. His data was from cells in culture. Then my PhD student wrecked his lab, and he wouldn't talk to me after that.

[individualmember]

Then my PhD student wrecked his lab, and he wouldn't talk to me after that.

I would like to nominate this as the finest ending of a post this year. Possibly century.

[wilsontown]

Indeed, there must be a story worth telling there...

[Al Capone Junior]

Calabrese's point seemed to be:

The LNT model is sh.t bc it assumes cumulative irreversible damage from even tiny levels of radiation (and other stuff)

It took him many years to come to accept this even tho his own research showed it. The LNT model is similarly entrenched as dogma all over the world, and must be changed.

Today he has a huge database of many things that follow a hermetic dose response curve, not a LNT one. This even applies to many highly toxic molecules such as ricin, which was very surprising

The harm is that making decisions based on the LNT model disconnects you from reality, causes irrationality in dealing with small quantities of risks, and contributes to the [Hiroshima syndrome].

The LNT model is scientifically bankrupt and fraudulent, but has become so deeply entrenched as dogma that even he had a hard time accepting the results of his own work

He had recently testified to a senate subcommittee

The EPA was moving away from using the LNT model, which was both a triumph for science and personally gratifying

He also has a large data set of substances that have a single exposure cancer risk. He donated use of his database to improve cooperation between regulatory bodies and academia

*****

How this interview wound up on this site I don't know. But on second look, yes, the site really is "twunty."

Nevertheless, any progress made in ridding the world of the LNT model* must be at least a small step towards the eventual acceptance of nuclear energy as a means to power a carbon neutral world.

*I once saw Hans Blix refer to the "Hiroshima model" in an interview about Chernobyl. I assume this is synonymous with LNT (but I could be wrong)

[Chris Preston]

pesticides

Just because I know about this one. For pesticides the assumption is that the dose response is sigmoidal. That is no observable effects at low doses, a linear phase at intermediate doses and complete mortality at high doses. It has proved to be a robust assumption and the variations from it have been relatively rare.

This means that the No Observable Adverse Effect Level is used as a regulatory endpoint to determine safe exposure limits. Because all pesticides go through multiple rounds of testing to find the NOAEL, there is often plenty of data on low doses.

As a first approximation, I would expect most other toxicity exposures to be similar. People often push other dose response models as being "normal", but they are usually doing it as a means of supporting their conclusions about toxicity rather than because they have real evidence. About the only other model that turns up with reasonable frequency is hormesis. There are some true classic examples of hormesis (Vitamin A), but many examples of hormesis are small and not worth focusing on for management purposes.

If the NOAEL is for practical purposes not different to 0 (that is, it is not possible to manage the exposure to below the NOAEL) then you would choose a no threshold management option.

[Chris Preston]

Today he has a huge database of many things that follow a hermetic dose response curve, not a LNT one.

I should hope not.

Hermetic: relating to an ancient occult tradition encompassing alchemy, astrology, and theosophy.

We prefer scientific rigor these days.

[plodder]

pesticides

Just because I know about this one. For pesticides the assumption is that the dose response is sigmoidal. That is no observable effects at low doses, a linear phase at intermediate doses and complete mortality at high doses. It has proved to be a robust assumption and the variations from it have been relatively rare.

This means that the No Observable Adverse Effect Level is used as a regulatory endpoint to determine safe exposure limits. Because all pesticides go through multiple rounds of testing to find the NOAEL, there is often plenty of data on low doses.

As a first approximation, I would expect most other toxicity exposures to be similar. People often push other dose response models as being "normal", but they are usually doing it as a means of supporting their conclusions about toxicity rather than because they have real evidence. About the only other model that turns up with reasonable frequency is hormesis. There are some true classic examples of hormesis (Vitamin A), but many examples of hormesis are small and not worth focusing on for management purposes.

If the NOAEL is for practical purposes not different to 0 (that is, it is not possible to manage the exposure to below the NOAEL) then you would choose a no threshold management option.

IIRC different regulatory environments (eg US vs EU) use slightly different approaches, with No Detectable Limits (I forget the formal acronym) featuring heavily in European legislation. This limit changes as detection technology evolves. Similarly as we get better at observing effects NOAEL can become stricter.

Agree it’s a sensible approach, just wanted to caution that just because we don’t think something is harmful it doesn’t mean it’s actually safe - if you get my drift.

[Allo V Psycho]

Indeed, there must be a story worth telling there...

Well, OK. One of my PhD students decided to use a really powerful mutagenic agent on cells in culture, but reckoned that telling us about it (so I could order it) would just be a pain, with COSHH forms to fill in, me giving stern safety lectures, and so on. She knew there was some in the lab next door, in a locked safe storage cabinet. And she knew where the key was (PhD students talk to each other). So she purloined the key, and then stole the agent. She did carry it downstairs to a Class II inflow cabinet in yet another (communal) lab, so she wasn't completely daft. But because she hadn't read a COSHH form or talked to anyone about it, she didn't know that the crystals in the vial built up an electrostatic charge when the vial was carried or agitated. So when she opened it in the inflow cabinet, the entire contents vented themselves into the cabinet.

That whole lab had to be shut down until men in space suits could come and dismantle the flow cabinet and take it away, presumably to drop the parts into molten metal or something. It was communal space, with a number of different containment facilities, including Class III cabinets, so no one could use it for a week till the space men got there.

Obviously, I got the blame, and true, in principle it was my responsibility. But I'm still not clear how I could have prevented it, short of having telepathic powers. From then on, we did include 'Do not steal really dangerous stuff from other people's labs' in our safety induction, but that hadn't occurred to me before.

Maybe this would be better in Nerd Lab!

[nekomatic]

That’s brilliant (in the sense of ‘terrifying and appalling’)

[Al Capone Junior]

Today he has a huge database of many things that follow a hermetic dose response curve, not a LNT one.

I should hope not.

Hermetic: relating to an ancient occult tradition encompassing alchemy, astrology, and theosophy.

We prefer scientific rigor these days.

Oops, spell check fail