How long does tobacco stay in your blood system?

I heard it was 72 hours as we are preparing to take a health exam for obtaining insurance,( we received this information from our insurance agent.) The rates are three times as much for tobacco users! three times 72 hrs.? have to take swab test I believe for job but not for health insurance. might be blood test but I doubt it. work in hospital and can't be fired............wondering if I'll be labeled a liar thanks

They actually check for cicotine - a metabolite of nicotine. Cicotine can stay in the body for up to 7 days after a nicotine dose.