I’ve used bananas as examples of radiation sources before, in terms of equivalent dose and the knee-jerk reaction to the mention of “radiation” in news stories.

Well, it turns out that the banana equivalent dose is a more common unit for dose comparisons than I had suspected — it even has its own wikipedia page

The average radiologic profile of bananas is 3520 picocuries per kg, or roughly 520 picocuries per 150g banana.[3] The equivalent dose for 365 bananas (one per day for a year) is 3.6 millirems.

I had given the radiation level for a banana as about 300 picocuries, so obviously I was estimating the banana as being 80 – 100 g, rather than the 150 g used here.