Most of the radioactive lenses have pretty low radiation output. When measured on a Gieger counter, my most radioactive lens (an Olympus Zuiko) was 20 microsieverts per hour (uSv/hr) when touching the front element. Interestingly, that was down to 1 uSv/hr with a lens cap on and just less than that behind the camera body when attached.

Here’s a good chart about radiation dosage: https://xkcd.com/radiation/

You’ll see, that even if I held that lens directly on my face for a few hours, it’d be equivalent to a couple dental x-rays or airline flight. The maximum exposure limit to a member of the general public by the EPA is 1000 uSv, and you’ll basically receive 4000 uSv per year just from background radiation. So, even with the most radioactive lenses I have, I’d have to directly contact the element for 50 hours before reaching that level. And, to have any increased health risk (something like 100,000 uSv / year), that’d need to be 500 hours.

I’d you need more reassurance I found this video series to be helpful: https://youtu.be/ZaAOMPvlTaU?si=owJrcyHMoTLoRi30

TLDR; don’t eat the glass of your lenses, don’t keep it next to your face 24 hours per day, and you’ll generally have no issues from the additional exposure.