Breast milk is best, but it could be better

A large family of organic and synthetic chemicals

PFAS are widely used in everyday products such as non-stick coatings for cooking food, water-repellent
or stain-resistant fabrics, and personal care products. They are a large class of more than 9000
structurally different compounds, many of which have been used since the 1950s [Glüge et al. 2020].
PFAS are often referred to as forever chemicals, since their chemical composition gives them excellent
persistence in the environment. They do not occur naturally, are widespread and resistant to
degradation, and have been detected in people and wildlife all over the world [Brase et al. 2021]. It soon
became clear that some PFAS were measurable in the serum of at least 95 % of the adolescent and adult
US population [Calafat et al. 2007].
Numerous recent contamination events triggered suspicion and fear of adverse health effects. The
concerns regarding the lack of robust information on PFAS concentrations in breast milk as well as the
implications for both breast-fed infants and their families were recently voiced by people living in
communities impacted by significant and known PFAS contaminations.
Are PFAS threatening the health of the youngest among us? Are they threatening future generations?
Are they threatening our biosphere? People have far too few answers to these questions.

A Canadian-American research group analysed few available data

To overcome the scarcity of available data, the researchers developed a model using the ratios of serum
to breast milk concentration published in the scientific literature to estimate the concentrations in
breast milk of four PFAS. The scientists focussed on 4 fluor compounds: perfluorooctanoic acid (PFOA),

perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), and perfluorononanoic acid

The comparison of measured and estimated concentrations in breast milk with screening values for
drinking water proved that the mean measured and estimated PFOA and PFOS concentrations in breast
milk exceeded screening values, sometimes by more than two orders of magnitude. By contrast, for
PFHxS and PFNA, most of the mean measured or estimated concentrations in breast milk were below
the drinking water screening values.
Building firm conclusions on data for four out of 9000 different molecules is almost impossible.
Nevertheless, these results are not meaningless. Everyone will agree that PFAS do not belong in breast

Cause for concern

A brief look at the data suggests there is a huge unknown. That children’s drinking water screening
values are exceeded does not indicate that adverse health effects will occur. This should not be
interpreted as a reason not to breastfeed. It does however indicate that the situation should be
thoroughly further evaluated and investigated. It is more than time to gain a better understanding of
environmental chemical transfer to an exceptionally important source of infant nutrition.
The authors caution against making recommendations, since limited data availability have so far not
enabled the uncertainties and accuracies of the estimated results to be correctly evaluated. Moreover, it
should not be forgotten that infant PFAS exposures originate in utero, and may also be due to food
sources and formula feeding.

Facing data gaps can lead to erroneous conclusions

The authors of the paper strongly remind their readers that the information is designed to highlight
important data gaps in their understanding of PFAS and breast milk. Nevertheless, some misuse the fact
that there is too little data available. Witness the statement by the director of 3M for Europe, the
Middle East and Africa, who recently claimed that “after more than 20 years of research we can decide
that there is no health impact, at the concentrations we see today and in the past” [Vanmeldert 2021].
How does he know? Can he produce the peer review papers that confirm his statement?

Whenever public health could be at risk, extreme caution is needed. When it comes to our children and
grandchildren, we cannot be careful enough. We are responsible for their future. They are still too
young and too powerless to assume the responsibility. Intergenerational responsibility is what adults
need to pay heed to!

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Brase et al. [2021]. Legacy and emerging per- and polyfluoroalkyl substances: analytical techniques,
environmental fate, and health effects, International Journal of Molecular Sciences 22, 3, 995
Calafat et al. [2007]. Polyfluoroalkyl chemicals in the U.S. population: data from the National Health and
Nutrition Examination Survey (NHANES) 2003–2004 and comparisons with NHANES 1999–2000,
Environmental Health Perspectives 115, 11, 1596 – 1602
Glüge et al. [2020]. An overview of the uses of per- and polyfluoroalkylsubstances (PFAS), Environmental
Science Process & Impacts 22, 12, 2345 – 2373
Kang et al. [2021]. Placental transfer and composition of perfluoroalkylsubstances (PFASs): a Korean
birth panel of parent-infant triads, Toxics 9, 7, 168
LaKind et al. [2022]. Current Breast Milk PFAS Levels in the United States and Canada: After All This
Time, Why Don’t We Know More?, Environmental Health Perspectives 130, 2, 025002
Vanmeldert [2021]. Directeur 3M herhaalt standpunt over PFOS: “Na 20 jaar onderzoek besluiten we dat
er geen impact is op gezondheid”, vrt nws,