Nicotine concentrations in urine and saliva of smokers and non-smokers.

Nicotine concentrations were measured in saliva and urine samples collected from 82 smokers and 56 non-smokers after a morning at work. Each subject answered a series of questions related to their recent intentional or passive exposure to tobacco smoke. All non-smokers had measurable amounts of nicotine in both saliva and urine. Those non-smokers who reported recent exposure to tobacco smoke had significantly higher nicotine concentrations (p less than 0.001) than those who had not been exposed; their concentrations overlapped those of smokers who had smoked up to three cigarettes before sampling had the greatest influence on nicotine concentrations (r=0.62 for saliva and r=0.51 for urine). Neither the nicotine for yield of cigarettes nor the self-reported degree of inhalation had any significant effect on nicotine concentrations.