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6 Risk Assessment and Management of Chemical Products
Eventually, the concentration in air will reach a steady state (c stst
air ):
c
stst
air =
˙
Mτ
V
(6.12)
With the steady-state concentration in air known, the concentration in the body
lipids resulting from exposure via inhalation can be calculated as:
dc lip (t)
dt
= D inh − k elim × c lip (t)
(6.13)
D inh =
1
m lip
× c
stst
air × Q inh × r
(6.14)
c lip (t) =
1 − e −k elim ×t
k elim
× D inh
(6.15)
Eventually, the concentration in the lipids will reach a steady state (c
stst
lip ):
c
stst
lip =
D inh
k elim
(6.16)
Figure 6.10 shows a plot of the resulting chemical concentration in the person’s
body lipids over time (as defined by Eq. 6.15) with a constant release rate ( ˙
M) of
288 ng/d.
Fig. 6.10 Modeled steady-state indoor air concentration (c
stst
air ), concentration in body lipids (c lip ),
and steady-state concentration in body lipids (c
stst
lip ) over time derived from a single-box model for
indoor air and a one-compartment pharmacokinetic model. This calculation assumes a constant
indoor air concentration with a release rate of ˙
M = 288 ng/d, τ = 0.278 d, V = 40 m 3 , Q inh =
19.2 m 3 /d, r = 1, m lip = 10 kg, and k elim = 0.384 d −1