Table 2 Smoke exposure measures and CO boost, by type of cigarette smoked; 2^nd, 3^rd, 4^th cigarettes averaged

Weight of tobacco mg per cigarette

496.5 (7.47)

695.3 (15.0)

<0.001*

Net weight of tobacco burnt, own cigarette brand, mg

400.3 (48.4)

552.4 (87.8)

<0.001*

CO increase per cigarette, ppm

4.37 (2.06)

4.24 (2.52)

0.846

CO ppm increase per g of tobacco burnt;

10.82 (4.98)

7.60 (4.26)

0.021*

Total smoke inhaled per cigarette (total puff volume) mL

952.1 (387.7)

742.6 (188.8)

0.025*

Smoke inhaled in mL, per g of tobacco burnt

2392.6 (1013.0)

1356.0 (321.4)

<0.001*

Smoke inhaled per day mL #

18803 (13030)

13242 (6738)

0.077

Puffs per cigarette, count

16.9 (5.2)

13.6 (5.4)

0.035*

Smoke volume per puff, mL

57.3 (17.1)

58.9 (16.8)

0.744

Smoke flow mL/second

33.9 (10.4)

35.2 (9.3)

0.663

Smoke peak flow ml/second

51.0 (18.2)

51.4 (14.0)

0.928

Duration per puff seconds

1.72 (0.40)

1.77 (0.45)

0.664

Average inter-puff interval, seconds

16.67 (9.44)

18.67 (7.11)

0.419

Time puffing per cigarette, seconds

28.4 (9.1)

22.4 (5.9)

0.012*

Puffing as % of time smoking

11.67 (4.51)

10.24 (3.58)

0.235

Minutes smoking, per cigarette

4.29 (0.99)

3.86 (0.96)

0.139

Cravings from after 1^st to after 4^th cigarette

24.2 (28.2) to 10.1 (21.6)

19.8 (25.2) to 6.1 (9.1)

0.332