Endocrine disruptors, invisible but everywhere

Endocrine disruptors - comic

Endocrine ?

According to wikipedia:

The endocrine system is the collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards distant target organs.1

The endocrine system is therefore the following organs: thyroid, ovaries, testicles, pituary gland… well, basically everything that regulates the growth, the metabolism, the sexual development, the cerebral development, the reproduction…2

So, you get it, the endocrine system, and therefore hormonal, is a big deal.

What do endocrine disruptors do?

Endocrine disruptors are natural or artificial chemicals that interfere with our endocrine/hormonal system.

Endocrine disruptors alter the usual performance of the organism by interacting with the synthesis, the degradation, the transport and the behavior of the hormones.3

So, the 3 disruption modes are:

  1. by imitating the action of a hormone (like contraceptives)
  2. by preventing the hormones from acting (by fixing themselves on the receptors)
  3. by interfering with the mechanism of productions of hormones or receptors

Endocrine disruptors mechanism - comic

These disruptors have thus a indirect toxic effect, that impacts your health or the one of your descendants.

By the way, the European court is actually trying to agree on a definition, sot that they can regulate them. But it sounds like it’s gonna take a while.

The most famous endocrine discuptors: pesticides, phtalates (plastic), paraben (cosmetics), bisphenol A (plastic), flame retardant (so that your couch doesn’t burn so fast), triclosan (antibacterial soap), etc.

So, what’s do we risk?

There are many prices to win: cancers (depending on hormones, so breast, uterus, prostate and testicles), congenital malformation, overweight, diabetes, developmental disorders (autism, hyperactivity, decrease in the intellectual quotient), and that might not be all.

So there is a lot in stake. And, contrary to what we may believe, a short exposure is not too dangerous: our hormonal system is gonna fix itself over time. On the other side, a chronic exposure, even if it’s low, is infinitely more harmful.

In short: the endocrine organs send messages (hormones) to other organs in order to tell them how to behave. If we are exposed to endocrine disruptors in a chronic way, the targeted organs may thus never act like the are supposed to.

The mechanisms that generate these diseases are very hard to discover…

Chemical formulas - comic
For once, the drawing is not from me. I’ve been lazy.

It is fucking hard to study the impacts of endocrine disruptors. The exposure undergoes what quantity, what duration, what exposure way, what repetitions? Are the molecules isolated or is it a “cocktail” of molecules? Is the exposure in utero? Or before puberty? After maybe? Are the effects on the subject or on its children? The number of combinations to study makes it a gigantic task. Especially since the endocrine system is complex and involves many different hormones that interact with each other…

If it’s difficult to study the mechanism, this does not prevent us from doing epidemiological studies to highlight the causal connections. And that’s exactly what scientists have started to do even before we can try and study the mechanisms in details.

For the general population, we undergo chronic exposure with a very low dose. So we shouldn’t get too worried (but still).

However, thousands of scientists and several sanitary agencies managed to show the link between endocrine disruptors and the diseases listed above.

Let’s see a famous example: the diethylstilbestrol (1950-1960) has been used to prevent spontaneous abortions. It was forbidden in France in 1977, after a link had been made with vagina, breast and uterus cancers on the daughters of the treated mothers.4

Other example, a CNRS team (famous French research institute) has formed a cocktail of 15 chemical products with concentrations that have been found in the human amniotic liquid. A short exposure of this blend on frog embryos revealed multiples impacts on the brain development. Decrease of the number of neurones, decrease of the mobility…5 Scary…

endocrine disruptors study on frogs - comic

Now that you are scared, where do we find them?

For most of the population, the main sources are: water, food, air and cosmetic products. Those are very low quantities, but in a steady way.

In professional environment, they are found in: agriculture, pharmaceutical and chemical industries, etc. In those cases, the concentration (and therefore the consequences on health) can be higher.

But if you dig a bit, endocrine disruptors can be found almost everywhere6:

  • in the water
  • in the food (pesticides)
  • in the air
  • in cosmetic products (paraben)
  • in the clothes
  • on the furniture
  • in plastic food packaging
  • but also in other plastic packagings
  • in dust
  • in contraceptives (logical)
  • in cigarette smoke
  • in the smoke of diesel motors
  • in urban cleaning products
  • in flame retardants
  • in disinfectants
  • and even in the fat of animals that underwent those chemical substances

Yup, they are everywhere…

Endocrine disruptors solution - comic

What can we do?

You can’t completely protect yourself against endocrine disruptors. They are everywhere. However, we can adopt some good habits in order do diminish the risks:

  • ventilate your rooms
  • eat organic
  • avoid plastic packaging (especially for food)
  • use glass or wood instead of plastic for your cooking instruments
  • use cosmetics that do not contain paraben

Why do people still ignore it?

On one side, the words are a bit complicated, and people might struggle understanding the stakes and the dangers. But above all, acting on it means reconsidering your way of living, which many people are not really willing to do.

What is more, the European Union keeps postponing the agreements on an efficient legislation about those disruptors. Of course, we could start with the simple precautionary principle, but once again, the power of the lobbies win…

After writing that article, my first act will be to replace my plastic water boiler by one with inox (you can also find some made of glass). And you, what actions are you gonna take right now? Leave a message in the comments.

  1. https://en.wikipedia.org/wiki/Endocrine_system
  2. http://www.inserm.fr/thematiques/sante-publique/dossiers-d-information/les-perturbateurs-endocriniens
  3. http://www.inserm.fr/thematiques/sante-publique/dossiers-d-information/les-perturbateurs-endocriniens
  4. http://ansm.sante.fr/var/ansm_site/storage/original/application/a2abb4db0658b1c97ade1be777f219ce.pdf
  5. Fini J.B., Mughal B.B., Le Mével S., Leemans M., Lettmann M., Spirhanzlova P., Affaticati P., Jenett A., Demeneix B.A. (2017) Human amniotic fluid contaminants alter thyroid hormone signalling and early brain development in Xenopus embryos. Scientific Reports. 7, 43786 ; doi: 10.1038/srep43786.
  6. http://www.asef-asso.fr/problematiques-emergentes/nos-syntheses/1553-les-perturbateurs-endocriniens-des-substances-toxiques-qui-nous-entourent-la-synthese-de-l-asef

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