But this is about a piss test, not hair test, so could this be done with urine too? Also don't human body produce nicotine naturally as a neurotransmitter (unli

But this is about a piss test, not hair test, so could this be done with urine too? Also don't human body produce nicotine naturally as a neurotransmitter (unlike THC etc), which means they need to use a range as a marker for "smoker" so there will be false positives, how do they deal with this?