I’d say it is. Tetanus is bacterial. Its not caused by rust. The rusty nail method of transmission isn’t from a nail in a building like the post. Its from barns: stepping on an exposed nail in the past often happened in old rotting barns where animals would have been kept. The bacteria would be in animal feces, and would be in the dust/dirt of the barn, which would coat old exposed nails; go deep in mostly anerobic tissue and the bacteria would infect the bloodstream.
A rusty nail in the city won’t have cow shit dust on it, so no tenanus.