Journal of Toxicology

Research Article

Modeling the Human Kinetic Adjustment Factor for Inhaled Volatile Organic Chemicals: Whole Population Approach versus Distinct Subpopulation Approach

Table 2

Physiological parameters distributions used in the Monte Carlo simulations of the internal dose metrics with the steady-state algorithm.
Parameter(a)Subpopulation
Median age (range)
Adults
41 (18–64)		Neonate
14 d (0–30 d)		Infants
6.5 m (1–12 mo)		Toddlers
2 (1–3)		Children and adolescents
12 (4–17)		Elderly
78 (65–90)		Pregnant women
29 (15–44)
Sampled parameters
 Body weight (BW)
 (Kg: m ± SD, range)		76 ± 17, 37–152(b)4 ± 1, 2–7(c)9 ± 2, 3–15(b)13 ± 2, 7–32(b)36 ± 16, 9–113(b)72 ± 16, 33–155(b)70 ± 18, 36–152(d)
 [CYP2E1]
 (pmol/mg MSP: m ± SD, range)		49 ± 2, 11–130(e)18 ± 14, 1–56(c)36 ± 21, 10–86(c)42 ± 18, 18–74(c)53 ± 23, 22–95(c) ( f ) ( f )
Calculated parameters(b), (g)
 Alveolar ventilation rate (Qp) = [ ( ( 0 . 2 5 1 9 × B W 0 . 7 6 0 9 ) + ( 0 . 2 5 0 8 × B W 0 . 7 8 1 5 ) ) / 2 ) ] × ” v a r i a b i l i t y t e r m "
( i . e . , 1 ± 0 . 1 ( 0 . 8 - 1 . 2 ) )
 Liver volume (Vl) = 0 . 0 5 0 1 2 × B W 0 . 7 8 × ” v a r i a b i l i t y t e r m "
( i . e . , 1 ± 0 . 1 4 ( 0 . 6 6 - 1 . 3 4 ) )
 Liver blood flow (Ql) = 0 . 9 2 × V l × ” v a r i a b i l i t y t e r m "
( i . e . , 1 ± 0 . 1 3 ( 0 . 6 7 - 1 . 3 3 ) )
( a ) Log normal distributions for sampled parameters and normal distributions for “variability terms.” All indicated means are arithmetic, except note ( e ) (see below). ( b ) P3M database [28]. ( c ) [19]. ( d ) Distribution for non-pregnant women taken from P3M database [28], and, to each of these values, the mean body weight increase at any week during pregnancy (normal distribution of 5 ± 4.4 kg (0–14.1)) based on data from ICRP was added [16, 29]. ( e ) (Geometric mean ± geometric standard deviation) [20]. ( f ) Same as for adults. ( g ) [16].
CYP2E1: cytochrome p-450 2E1; MSP: microsomal protein; SD: standard deviation.