Levels of cigarette availability and exposure in black and white women and efficient smokers.

Purposes of this investigation were to examine differences in smoke exposure and smoking topography across three smoking conditions: usual number of cigarettes, restricted (50%) and increased (167%) simulating restricted and unrestricted cigarette availability. A repeated-measures counterbalanced design with a sample of 25 women (13 African Americans; 12 Caucasians) was implemented with a 6-day inpatient protocol conducted in the General Clinical Research Center (GCRC). There were significantly larger percentage increases in carbon monoxide (CO) postcigarette in the restricted condition compared to usual and increased condition. Women with baseline cotinine/cigarette ratios >20 ng/ml/cigarette, considered efficient smokers, had significantly higher CO increases postcigarette at baseline than participants with lower cotinine/cigarette ratios, yet increased this exposure further during the restricted condition. Efficient smokers had significantly higher nicotine boost in the restricted condition compared to less efficient smokers. Differences by ethnicity were also noted with significantly higher CO percentage increases pre- to postcigarette in African Americans across all conditions, compared to Caucasians. Levels of smoke exposure postcigarette in persons who reduce cigarettes per day in response to restricted cigarette availability may be substantial.