Penn State researchers studied 2,000 adult smokers who participated in the U.S. National Health Nutrition Survey, and the 2,000 respondents provided information on their blood samples and smoking habits. The researchers found that 32 percent of the people started their first cigarette within five minutes of waking up in the morning. Of the rest, 31% smoked their first cigarette within 6-30 minutes, 18% smoked their first cigarette within 31-60 minutes, and 19% smoked their first cigarette an hour later. The researchers found that regardless of the total amount of cigarettes smoked, the concentration of NNAL in the blood of those who smoked immediately after waking up in the morning was significantly higher than those who started smoking their first cigarette one hour later (NNAL is a tobacco-specific carcinogenic component). In addition, the researchers found that blood NNAL concentrations were associated with the smoker’s age, gender, age of initiation, and the presence of other smokers in the household. According to Professor Branstetter of Penn State University, “Most importantly, NNAL concentrations were highest in people who smoked immediately after waking up, regardless of the other factors mentioned above.” They suggest that smoking immediately after waking up is associated with a deeper and more complete inhalation of smoke, which is why they have better blood levels of NNAL and a higher risk of oral cancer. Therefore, the time of day when the first cigarette is smoked is an important indicator to identify which smokers are more likely to develop oral cancer.”