Table 3.

Exposure conditions for comparing target tissue doses in rats at NOAEL levels in subchronic inhalation bioassays and humans exposed via mainstream cigarette smoke

	Acrolein	Source	Acetaldehyde	Source	Formaldehyde	Source
Rat
Subchronic NOAEL ppm	0.2	a	50	b	1	c
BW (kg)	0.3	d	0.3	d	0.3	d
Breathing rate (minute volume; MV) (ml/min)	217	e	217	e	217	e
Breathing frequency (Breaths/min)	100	f	100	f	100	f
Human (male)
Body weight (kg)	72	d	72	d	72	d
Cardiac output (Q)
Total (Q, ml/min)	5920.6	g	5920.6	g	5920.6	g
Cigarette Yield (µg/cig)	100	h	857	h	61.2	h
Puffs/cig	11	i	11	i	11	i
Amount/puff (µg)	9.09	j	77.91	j	5.56	j
Volume oral cavity (ml)	42.07	k	42.07	k	42.07	k
Initial concentration oral cavity (ppm)	94	l	1,028	l	108	l

^aDorman et al. (2008a).

^bDorman et al. (2008b).

^cUS EPA (2010).

^dBody weight of rat or human used to develop model.

^eSchroeter et al. (2008).

^fAssumed 100 bpm for these simulations. Typical range is 70–115 bpm (Harkness et al., 2010).

^gCalculated as Q (ml/min) = 15 l/h/kg * (BW, kg)^0.74 * 1000 ml/l * 1 h/60 min. Distribution (fraction of cardiac output, Q_b) to each airway subepithelium as described by Corley et al. (2012) with the exception of acetaldehyde where nasal blood flows were based upon Teeguarden et al. (2008) and vasodilation occurs at concentrations >25 ppm (see Methods).

^hOverall average of yield in use data for RJR low and high tar brands (Kathman, S.J. personal communication). Estimated yields are within published ranges for Phillip Morris products and reference cigarettes (Counts et al., 2005).

ⁱDHHS (1988).

^jCalculated.

^kActual geometry from human oral model described in text.

^lCalculated from yield data and actual geometry: Conc. (ppm) = $\frac{\text{(Yield/cig)}·(\text{24451)}}{\text{(Puffs/cig)}·\text{(Vol. Mouth)}·\text{(Mol. Wt.)}}$.