Intake of fish-derived compounds in infants: Difference between revisions
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'''Exposure based on mother's diet | '''Exposure based on mother's diet | ||
If the infant is only breast-fed, | If the infant is only breast-fed, he gets 100 % of his energy intake from mother's milk. It can be reasonably assumed that the infant gets the same proportion of other compounds from mother's milk as what he gets energy. The concentrations of these compounds in mother's milk, on the other hand, are relative to their amounts in mother's diet. Of course, there may be large deviations from this assumption depending on the compound, but these are not dealt with in this phase. | ||
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Therefore, fish intake is a product: | |||
I<sub>i</sub> = Σ<sub>t</sub> I<sub>t,m</sub> * (E<sub>t,i</sub>/E<sub>t,m</sub>) * F<sub>t,i</sub>, | |||
where I = annual intake, E = energy intake, F = fraction of the breast milk from the total diet, t = time, i = infant, m = mother. As a first proxy, F is 1 with breast feeding only, 0.5 with additional breast feeding, and 0 otherwise. | |||
'''Mother's body burden | '''Mother's body burden | ||
In the case of [[PCDD/F]]s, the mother may have a large body burden already before pregnancy, and these pollutants are then transferred to the infant during breast-feeding. Even 25 % of mother's [[PCDD/F]] body burden may be transferred to the infant during breast feeding <ref>Oral information from Terttu Vartiainen. This has also been published somewhere, it should be found.</ref>. | In the case of [[PCDD/F]]s, the mother may have a large body burden already before pregnancy, and these pollutants are then transferred to the infant during breast-feeding. Even 25 % of mother's [[PCDD/F]] body burden may be transferred to the infant during breast feeding <ref>Oral information from Terttu Vartiainen. This has also been published somewhere, it should be found.</ref>. | ||
The average contaminant intake is | |||
I<sub>c,i</sub> = C<sub>0,m</sub> * m<sub>m</sub> * (1-e<sup>-k<sub>n</sub>t<sub>n</sub></sup>), | |||
where C<sub>0</sub> is the concentration in the beginning, k<sub>n</sub> = elimination constant for the compound in the mother due to nursing, t<sub>n</sub> = length of the nursing period, c = compound, n = nursing. | |||
For [[PCDD/F]] (see above), k<sub>n</sub> can be calculated from | |||
1-e<sup>-k<sub>n</sub>*0.5 a</sup> = 0.25 ⇔ k<sub>n</sub> = 0.575364 1/a | |||
Latest revision as of 08:43, 13 August 2009
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Scope
What is the intake of fish-derived compounds in infants (below 1 year of age)?
Boundaries:
- Averaging: A random individual
- Spatial: In Finland
- Temporal: Current situation
Definition
Data
There are several possible pathways of intake:
- Being exposed to the compounds in utero, so that there is a body burden at birth.
- By breast feeding.
- Exposure based on mother's current diet.
- Exposure based on mother's body burden (because of previous exposure).
- Eating fish-containing food.
In utero exposure
Placental concentrations of PCDD/Fs and methyl mercury can be used as proxies of body burdens at birth. Whether these should be transformed into other units (concentrations in child, or steady state daily intake), needs to be discussed.
Breast feeding
| Age (mo) | Additional breast-feeding | Only breast-feeding |
|---|---|---|
| 1 | 0.92 | 0.58 |
| 3 | 0.33 | |
| 4 | 0.72 | 0.21 |
| 6 | 0.58 | 0.01 |
| Average time | 7 mo | 1.4 mo |
Exposure based on mother's diet
If the infant is only breast-fed, he gets 100 % of his energy intake from mother's milk. It can be reasonably assumed that the infant gets the same proportion of other compounds from mother's milk as what he gets energy. The concentrations of these compounds in mother's milk, on the other hand, are relative to their amounts in mother's diet. Of course, there may be large deviations from this assumption depending on the compound, but these are not dealt with in this phase.
| Age | Energy (MJ/day) |
|---|---|
| 0-3 mo | 1.3-2.2 |
| 4-5 mo | 2.6-2.7 |
| 6-12 mo | 2.6-3.7 |
| 12-23 mo | 3.4-5.5 |
| 2-5 a | 5.3-6.3 |
| 6-9 a | 7.2-9.2 |
| Boys | |
| 10-14 a | 9.4-10.8 |
| 15-18 a | 11.3-13.4 |
| Girls | |
| 10-14 a | 8.2-9.5 |
| 15-18 a | 9.6-9.9 |
Therefore, fish intake is a product:
Ii = Σt It,m * (Et,i/Et,m) * Ft,i,
where I = annual intake, E = energy intake, F = fraction of the breast milk from the total diet, t = time, i = infant, m = mother. As a first proxy, F is 1 with breast feeding only, 0.5 with additional breast feeding, and 0 otherwise.
Mother's body burden
In the case of PCDD/Fs, the mother may have a large body burden already before pregnancy, and these pollutants are then transferred to the infant during breast-feeding. Even 25 % of mother's PCDD/F body burden may be transferred to the infant during breast feeding [3].
The average contaminant intake is
Ic,i = C0,m * mm * (1-e-kntn),
where C0 is the concentration in the beginning, kn = elimination constant for the compound in the mother due to nursing, tn = length of the nursing period, c = compound, n = nursing.
For PCDD/F (see above), kn can be calculated from
1-e-kn*0.5 a = 0.25 ⇔ kn = 0.575364 1/a
Fish-containing food
The recommendation is that infants don't eat fish at all before 6 months of age, and it is gradually added to the diet. Therefore, it can be assumed zero intake until 6 mo, and then a linear shift to the individual fish intake level at 1 year of age.
Dependencies
Unit
g/day (of fish), or g/day (of a specific compound); the matrix must be specified!
Formula
Result
{{#opasnet_base_link:Op_en3590}}
See also
References
- ↑ Breast feeding in Finland
- ↑ Therapia Fennica
- ↑ Oral information from Terttu Vartiainen. This has also been published somewhere, it should be found.