Breast milk sampling is a non-intrusive way of determining contaminant exposure of infants and a useful biomonitoring tool. Breast milk sampling has been used to test for POPs globally for several decades and is a good indication of regional intake from diet and environmental pollution.
- Identify volunteers, preferably women at 2 to 4 weeks post-partum (UNEP 2007);
- Prepare sampling materials and interviews;
- Have the necessary personal protective equipment to treat the breast milk as a bio-hazard.
Clean Sample Equipment
- Mothers are to be provided with a sealed sample jar.
The key components of the breast milk sampling program:
- all potential breast milk donors are provided with a personal identification number (medical wrist band), used to assist the study team identify each individual sampled;
- detailed interviews are conducted prior to collection of blood samples;
- do not composite milk samples in the field; all compositing of samples should be preformed in the laboratory.
Breast milk samples are to be collected from volunteer donors. It is recommended that 50 samples are collected for statistical representation (UNEP 2007). Mothers are asked to provide information on age, number of children and number of children which they have breastfed (including children of relatives, etc.). Breast milk sampling should be conducted at the same time as the blood sampling program; some mothers donate both blood and breast milk samples. Volunteer patients should donate 15-50 cc of breast milk sample; milk will be expressed by individual mothers directly into the sample jar. A minimum of 20 milk samples should be collected from each of target sample communities.
The breast milk phase of the program serves two purposes:
- given the close relationship between blood and breast milk PCDD/PCDF levels, single milk samples should be analyzed to provide an indication of PCDD/PCDF variability in the communities; these data were to provide another indication of the relative degree of variability that may occur in blood on an individual sample basis, given blood analyses are often performed on composite samples only; and
- given that breast milk constitutes a significant portion of the diet of infants, and given that other infants may be fed by the same mother in some communities, knowledge of breast milk contamination would serve to clarify an additional route of human contamination in addition to that caused by the ingestion of other contaminated foods and/or dermal exposure through contact with contaminated soils.
For more information see the UNEP document: Guidance on the Global Monitoring Plan for Persistent Organic Pollutants (PDF file - 2007).