A Letter to my Fellow Hormetians

Many people who recognize LNT's disastrous invalidity are uncomfortable with SNT because SNT does not incorporate hormesis, the theory that too little radiation can be bad for you. There is compelling evidence, that that can be the case. So in that sense I'm a hormetian. The problem is defining which dose rate profiles are beneficial.

I believe that it is difficult to argue that the dose rate profiles associated with a nuclear power plant release are good for you. Hormesis works by stimulating repair processes which end up repairing more DNA damage than they cause. But stimulating such responses over and over again by dose rates that are an order of magnitude or more above normal background is unlikely to be net beneficial. But what is certain is that, for regulatory purposes, the hormetian must delineate at what point does repeated stimulation become ineffective and then harmful.

Any LNT replacement model must be completely defined. By that I mean, it must be able to convert any arbitrary dose rate profile into a quantitative prediction of cancer incidence/reduction. LNT can do that. SNT can do that. This capability is required:

1) to set reasonable, consistent limits/triggers and the penalties/responses for exceeding those limits,

2) to properly design a compensation program for exposure to radiation.

I am unaware of any completely defined hormetian or threshold model. It is incumbent on the hormetian to produce that model. So far they have not.

The standard LNT defense is to claim there is no threshold and challenge the thresholder to state his threshold and prove that there is always zero or negative harm up to that threshold. Unless he is able to do that, the LNTer fallaciously claims the only model we are left with is LNT. This puts the thresholder in a very difficult position. Worse, it focuses the debate on the existence of a threshold rather than LNT's dismissal of our indisputable ability to repair DNA damage.

By embracing the No Threshold doctrine, SNT takes away the LNTer's only defense. Just as importantly, SNT focuses the debate on the existence of our DNA repair system. SNT does not claim to be a accurate model of that repair system, which can result in radiation being beneficial in certain situations. It only claims to be far better than LNT, multiple orders of magnitude better when a dose is spread over many repair periods. SNT focuses the argument on LNT's fundamental error.

It also turns the switch from LNT to SNT into an upgrade. It does not ask the LNTer to abandon his cherished No Threshold dogma.

It only asks him to believe the RERF when the say their new data, based on much improved dosimetry, is clearly non-linear.\cite{grant-2017,brenner-2022}

It only asks him for a tweak on LNT that allows the upgraded LNT to explain the lack of detectable harm when extremely large doses are received more or less evenly over long periods.

It only asks him for a tweak on LNT that admits that space travel is possible.

It only asks him for an upgrade to LNT that makes the upgraded LNT consistent with our amazing ability to repair DNA damage, an ability about which we knew very little when LNT was adopted 75 years ago.

Finally, SNT is intentionally conservative. For the purposes of regulation, SNT purposely errs on the pessimistic side. One aspect of that pessimism is avoiding trying to delineate which profiles are net beneficial. SNT does not deny the existence of hormesis any more than it denies the fact that the DNA repair time is dose rate dependent. It just says that in the interests of conservatism and parsimony, I'm going to ignore these phenomena.

The bottomline is simple. Given adequate buffer zones, the dose rate profiles experienced by the public in a nuclear power plant release will almost always have no detectable effect, positive or negative. SNT is consistent with this fact. It's all we need. And it's probably all we can get.