So? That doesn't mean they landed on the roof from space. The really tiny stuff can be blown around. It may land on the ground at point A and then be blown onto a roof miles away at point B. This is why we should not use the simple math of a roof's size to determine the rate of material falling from space.
Some of the earth is decayed earlier material - radon gas formed here on earth as a daughter product from uranium in granite.
Some of the earth has been created by man on earth in the atomic age ... all those extra elements tacked to the end of the periodic table.
Don't those decay immediately? They would account for 0% of the earth.
Granted, that's an isotope of a well-known element, not one of the "extra elements tacked to the end of the periodic table". I can point out that [tiny traces of plutonium-244 have been found in the ocean seafloor](https://www.npr.org/2021/05/13/996499035/freshly-made-pluton...). That has a half-life of about 80 million years; it's probably the result of ejecta from a supernova washing over the Earth several million years ago.
There are a lot of isotopes.