Validating reports of nonsmoking with breath and saliva samples: your checkup is in the mail

Reports of nonsmoking are usually validated by obtaining breath carbon monoxide levels or saliva thiocyanate levels. However, it is often not convenient to obtain such samples from persons who participated in a smoking cessation program long in the past. Obtaining the samples through the mail could help solve this problem, but it is possible that the time the samples spend in the uncontrolled environment of the mails might invalidate the measured levels. The present study was to see whether that possibility was indeed a real concern. Breath and saliva samples were collected in airtight containers and allowed to remain in an uncontrolled environment (60 degrees-80 degrees F) for 72 hours, 24 hours, and less than one hour. The results suggest that the time spent in this environment had minimal impact on the carbon monoxide or thiocyanate levels in smokers' or nonsmokers' samples. Even after 72 hours, the samples could differentiate smokers from nonsmokers with little overlap. It appears that breath and saliva samples can be conveniently obtained through the mail without sacrificing their usefulness.