[acidburnNSA]

For context, the 0.1 rem yearly dose to the patient is about 1/6th of the average background dose we all get every year.

This Pu-238 is the same stuff that's powering the Voyager probes and a few Mars rovers.

Note that it's not Pu-239, which is fissile nuclear fuel for chain reactions (power plants, bombs, etc.)

[stinkbeetle]

> For context, the 0.1 rem yearly dose to the patient is about 1/6th of the average background dose we all get every year.

Wouldn't you be more concerned about dose rates in tissues near the device though, rather than whole body dose? At the surface of the pacemaker it would be about 90 rem / year.

[BurningFrog]

Since it's a device that saves the life of the patient, you can accept a lot of patient risk as a tradeoff.

[stinkbeetle]

Obviously. That doesn't address my question though, the dose of concern is surely the nearby tissue rather than one calculated over the whole body. If the pacemaker is resting against my lungs, I'm not going to be concerned about foot cancer.

I'm not implying the risk was miscalculated in the medical approval process, I'm sure it's safe enough. I'm just questioning OP's statement about radiation dose, yes it's strictly true but seems to underplay the importance of the nature of the dose.

[SoftTalker]

Pu-238 decays mainly by alpha decay which would be easily contained by the titanium casing.

[cyberax]

It also spontaneously fissions, with daughter products often being gamma/beta active. And it always contains some contaminants

[stinkbeetle]

Thanks. Presumably we're talking about "Dose rates at the surface of the pacemaker are approximately 5 to 15 mrem per hour from the emitted gamma rays and neutrons" though.

[SoftTalker]

Yeah ideally I would not want that in or close to my body but if the choice is literally life or death I guess I'll take it.

How do modern pacemakers work? Can they be recharged inductively or is surgery required to replace batteries periodically?

[kondro]

REM is already an adjusted measure for absorption, not an general quantity of radiation.

[stinkbeetle]

This doesn't address my question. OP was talking about the whole-body dose, I'm asking about the surface and nearby dose.

[jmb99]

If I die without a pacemaker, or maybe have an increased risk of certain cancers with a pacemaker but get to live, I’d choose the pacemaker.

[stinkbeetle]

Duly noted.

[_kb]

Or approximately 100 bananas, for scale.

[acidburnNSA]

Banana equivalent dose is 0.01 mrem, so 0.1 rem = 100 mrem = 10,000 bananas.

[ChuckMcM]

Yeah but their spouse :-) 75x larger dose.

[acidburnNSA]

No it's less! They switched from rem to millirem for the spouse.

[ChuckMcM]

Dang! Me and my misreading of the units. That makes more sense too.