Infant's dioxin exposure

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Question

How to measure infant's dioxin exposure due to fetal period and breast feeding?

Answer

Mother's exposure at level 100 pg /d (fairly typical amount) will lead to child's TEQ concentration of 44 pg /g fat (logTEQ 3.8).

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Rationale

Transformation between serum concentration and intake:

C_s = \frac{I * t_{1/2} * f}{a * ln2 * BF%},
where
Cs = serum concentration of dioxin in pg/g fat
I = average daily intake of dioxin in pg/kg/day
t1/2 = the half-life of dioxin (2737.5 d = 7.5 a)
f = fraction of ingested dioxin actually absorbing from the gut (0.80)
BF% = body fat percentage
a percentage of total daily dietary intake of dioxins that come from fish (0.86).

The previous equation applies in a single individual. In the case of dental aberrations, the main exposure comes from the mother during pregnancy and breast feeding. For this, we use

C_{s,i} = \frac{I_{a,m} * t_{1/2,m} * f_m * FE}{ln2 * BF_i},
where
Cs,i = serum concentration of dioxin in the infant in pg/g fat
Ia,m = average daily intake of dioxin of the mother in absolute amounts pg/day
t1/2,m = the half-life of dioxin in the mother (2737.5 d = 7.5 a)
fm = fraction of ingested dioxin actually absorbing from the gut in the mother (0.80)
FE = fraction of mother's dioxin load that is transported to the infant during breast feeding (0.25) Vartiainen et al. REF
BF = body fat amount in the infant (into which the dioxin is evenly distributed) during the period when tooth are sensitive to defects and the exposure at its highest (ca. six months of age) (1 kg)

Inputs

Parametres(-)
ObsParametreValueDescription
1TEQ half-life2737.5t0.5: 7.5 * 365, Dioxin half-life in adults (d)
2TEQ fraction absorbed0.8f_ing: 0.80, Fraction of dioxin ingested that is actually absorbed (-)
3TEQ fraction to child0.1 - 0.25f_mtoc: 0.25, Fraction of mother's dioxin burden that enters the child during breast-feeding in 6 mo. Alaluusua et Vartiainen (-)
4Body fat in infant1580BF: 0.2 * (7.692+8.141) / 2, body fat amount in the infant at six months of age (g) [[:op_en:Body weight of 0-24 months old Finnish children]].

Calculations

  • Ovariables initiated 19.5.2017 [1]
  • Updated 30.5.2017 [2]

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See also