My guess is that a given atom in your body has been there for an average of a few months, with a wide distribution between a couple days (water) to a lifetime (stable molecules in e.g. DNA from infancy). And so I’d guess most of our weight in atoms is recycled at least every few weeks.
The picture this paints is one in which we are not so much solid, isolated objects; and more like patterns surviving through time.
The physicist Max Tegmark suggests a picture of life as a ‘braid’ in space through time.
If that’s right, then the threads of the braid that makes up a person run through skies, seas, other life, and through the machines of industry. A person’s braid isn’t isolated through their life, but ephemeral; swapping threads with the wider world until the point of death, where the threads that now make up the braid — few of the originals remain — disperse again.