In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.
One example: when are hops added to the brewing process?
Solution is here: The boiling process
Explanation: The answer is correct because, at the end of the boil, solid particles in the hopped wort are separated.

Now, solve this: when was smoking first known to be harmful
Solution:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Early 17th century