Manmade perfluorinated chemicals (PFCs), regarded for their oil- and water-repellent properties, have been used in a wide range of products, such as non-stick cookware and food packaging, since the 1950s. Increasingly, scientists warn that PFCs can now be detected everywhere in the environment and even in our bodies.

Most of us ingest small amounts of PFCs through food and water. So far, animal studies have shown that PFCs delay developmental growth but their effects on human health have been less clear.

Researchers in Japan have, for the first time, established a link between PFCs in maternal blood and levels of cord blood hormones at birth.

Their study is part of a large-scale, ongoing project called the Hokkaido Birth Cohort Study on Environment and Children’s Health, which monitors the health of children born in this region of northern Japan.

The team measured PFC levels in the blood of 185 expectant mothers, and subsequently measured cord blood levels of two groups of steroid hormones in their newborn babies: glucocorticoids (cortisol and cortisone) and androgens, both of which play an important role in controlling human metabolism and reproduction.

They found that foetal exposure to a common PFC contaminant, called perfluorooctane sulfonate (PFOS), was linked to lower levels of cortisol and cortisone in cord blood. PFOS was also associated with higher levels of the androgenic hormone dehydroepiandrosterone (DHEA).

This “may have adverse effects on the foetal endocrine system and steroid hormone homeostasis in later life resulting in abnormalities in growth, neurodevelopment and reproductive health,” says Reiko Kishi from the Center for Environmental and Health Sciences at Hokkaido University. “Therefore, in utero PFC exposure may be a public health concern, and long-term observation of these effects is warranted.” Although PFCs are being phased out by certain industries, they are still present in older products, and can accumulate in our bodies. A previous study by the same research team warned that new types of PFCs with longer carbon chains were increasing. As these PFCs are known to have greater toxicity and longer half-lives, the researchers emphasise that awareness of associated risks needs to be raised.

Recommendations for expectant mothers and those who are now breastfeeding include avoiding foods packaged in materials containing PFCs (such as microwave popcorn bags, fast food containers and pizza boxes); minimising dust ingestion and hand-to-mouth transfer, and avoiding the use of groundwater for drinking or cooking. Kishi says that collaborating and integrating existing birth cohort studies across borders will become more important. To this end, she led the launch of the Birth Cohort Consortium of Asia (BiCCA) in 2012, which aims to deepen understanding of the health impacts of a wide range of environmental chemicals and to develop effective prevention strategies for children’s health.

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