How long for second hand nicotine in blood?

Secondhand nicotine can remain in the bloodstream for a variable amount of time, depending on factors like the duration and intensity of exposure. Typically, nicotine itself is metabolized quickly, with a half-life of about 1 to 2 hours. However, metabolites such as cotinine can be detected in the blood for much longer, often up to several days after exposure. Thus, while nicotine from secondhand smoke may clear rapidly, its effects can linger longer through its metabolites.