Endocrine Disruptors : from Scientific Evidence to Human Health Protection

The European Parliament publishes new report on endocrine disrupting chemicals, 2019

The European Society of Endocrinology welcomes the new European Parliament report on Endocrine Disrupting Chemicals (EDCs) written by Prof Barbara Demeneix of the Muséum National d’Histoire Naturelle in Paris, France and member of the ESE EDC Working Group and Dr Rémy Slama, INSERM (National Institute of Health and Medical Research), Grenoble, France.

Abstracts

Presentation

This study, commissioned by the PETI Committee of the European Parliament, presents the scientific knowledge regarding the health effects of endocrine disruptors, a class of hazards recognized in EU regulation since 1999. This report reviews the scientific evidence regarding the concept of endocrine disruption, the extent of exposure, associated health effects and costs. The existing relevant EU regulations are discussed and recommendations made to better protect human health.

1.1.2 The drug diethylstilboestrol (DES)

DES was developed as a synthetic oestrogen. It was prescribed from the 1940s onwards. Prescriptions were based on the erroneous assumption that it could prevent miscarriage and other pregnancy complications, which was shown to be wrong in 1953. In 1971, the USA Food and Drug Administration (FDA) advised against its use due to vaginal cancers occurrence in girls born to mothers who had used DES, while this cancer usually develops post-menopause. DES was banned in the Netherlands in 1975 and in France and Spain in 1977. Women who took DES have a slightly higher risk of breast cancer, but the most striking effects are seen on offspring exposed during pregnancy. Epidemiology shows in utero DES exposure to be linked not only to vaginal cancer in daughters of exposed women, but also to reproductive tract disorders, infertility and higher rates of spontaneous abortion. Sons display higher rates of genital abnormalities, and increased risks of prostate cancer; in addition, an increased risk of testicular cancer has been suggested. Importantly, effects such as increased risk of malformations of the male genitalia and possibly attention deficit and hyperactivity disorders (ADHD) are also observed in the grandchildren of DES-prescribed women.

In contrast to DDT, which is persistent in the body, DES is quickly eliminated, showing that chemicals can exert effects long after they disappeared from the organism, possibly on successive generations. There are biological mechanisms whereby the organism could keep a memory of exposure. One possibility relates to adverse effects that can be traced to epigenetic modifications. Work on animal models shows that certain DES impacts could result from epigenetic effects on the germ cells (the sperm and egg cells) forming in the in utero DES exposed foetuses).

Both DDT and DES provide examples of compounds able to interact with the endocrine system in humans or wildlife species (DES was designed to mimic a natural hormone, oestrogen; DDT and its metabolites were found to alter hormone production, mimic oestrogen and block androgen actions) and to cause adverse effects. They resonate with a concept developed in 1.7 and 1.9: the Developmental origin of Health and Disease (DOHaD), underlining foetal life as a determinant factor for child and adult health.

The scientific report, commissioned by the Parliament’s Committee on Petitions, provides an excellent overview of the severe threat EDCs pose for EU society and highlights the many shortcomings of current EU policies and legislation. Amongst the many proposed regulatory measures, it urges the European Union to rapidly develop a set of trans-sectorial and harmonised regulations to minimise human and environmental exposure to EDCs. As discussed in the report, based on an extensive literature review, EDCs or suspected EDCs are currently present in all media (water, diet, food contact materials, cosmetics…) and most EU citizens have dozens of (suspected) EDCs in their bodies.

In addition to improved regulatory measures, the report stresses the importance of speeding up test development to effectively identify EDCs and calls for additional research to address the many knowledge gaps in this relatively new scientific area.

These calls for additional regulation and research at the EU level are in line with a recent ESE Statement in response to the disappointing European Commission Communication on EDCs from 7 November 2018, which in ESE’s view lacks ambition to effectively tackle the many challenges in this area.

DES DiEthylStilbestrol Resources

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