Découverte de l’impact du Pyriproxyfène sur l’augmentation de graves malformations chez les bébés nés au Brésil

Environmental Pollution via le Muséum National d’Histoire Naturelle (MNHN)
De Pieter Vancamp, Petra Spirhanzlova, Anthony Sébillot, Lucile Butruille, Jean-David Gothié, Sébastien Le Mével, Michelle Leemans, Karn Wejaphikul, Marcel Meima, Bilal B. Mughal, Pierre Roques, Sylvie Remaud, Jean-Baptiste Fini, Barbara A. Demeneix

07/23/2021

@Pixabay

En 2015, l’augmentation du nombre de bébés nés au Brésil avec une microcéphalie (petite tête et petit cerveau) a inquiété le monde entier. Cette grave malformation était associée à l’infection des femmes enceintes par le virus ZIKA, véhiculé par le moustique Aedes aegypti. Une étude de chercheurs de l’UMR PhyMA (Département Adaptation du Vivant – Muséum national d’Histoire naturelle et CNRS) parue dans la revue Environmental Pollution suggère que le Pyriproxyfène, un insecticide utilisé de manière intensive au Brésil, pourrait être un facteur majeur contribuant à l’augmentation de l’incidence de la microcéphalie.

Le Pyriproxyfène perturbe l’action des hormones thyroïdienne, qui contribuent à faire fonctionner le cerveau humain. Une carence grave en hormones thyroïdiennes pendant la grossesse était autrefois une cause fréquente de l’état pathologique de crétinisme, qui s’accompagnait de petits cerveaux et engendrait des handicaps mentaux chez les enfants.

Le rapport scientifique confirme que la perturbation de l’action des hormones thyroïdiennes, due à l’exposition au Pyriproxyfène, est impliquée dans la microcéphalie. L’insecticide dérèglerait des gènes impliqués dans la régulation de la génération des neurones et des cellules gliales, les éléments de base du cerveau. Le virus du ZIKA aggrave également les effets induits par l’insecticide sur le développement du cerveau. Les chercheurs démontrent donc que le Pyriproxyfène est un antagoniste actif des hormones thyroïdiennes, qui modifie le développement correct du cerveau.

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Thresholds and Endocrine Disruptors: An Endocrine Society Policy Perspective

Journal of the Endocrine Society
From Barbara Demeneix, Laura N Vandenberg, Richard Ivell and R Thomas Zoeller

07/09/2020

Abstract

The concept of a threshold of adversity in toxicology is neither provable nor disprovable. As such, it is not a scientific question but a theoretical one. Yet, the belief in thresholds has led to traditional ways of interpreting data derived from regulatory guideline studies of the toxicity of chemicals. This includes, for example, the use of standard “uncertainty factors” when a “No Adverse Effect Level” (or similar “benchmark dose”) is either observed, or not observed.

In the context of endocrine-disrupting chemicals (EDCs), this approach is demonstrably inappropriate. First, the efficacy of a hormone on different endpoints can vary by several orders of magnitude. This feature of hormone action also applies to EDCs that can interfere with that hormone. For this reason, we argue that the choice of endpoint for use in regulation is critical, but note that guideline studies were not designed with this in mind.

Second, the biological events controlled by hormones in development not only change as development proceeds but are different from events controlled by hormones in the adult. Again, guideline endpoints were also not designed with this in mind, especially since the events controlled by hormones can be both temporally and spatially specific. The Endocrine Society has laid out this logic over several years and in several publications. Rather than being extreme views, they represent what is known about hormones and the chemicals that can interfere with them.

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European strategy aims to rein in EDC exposures

Endocrine Today
From Regina Schaffer

10/28/2020

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The European Commission this month unveiled their new chemicals strategy for sustainability, designed to protect the public from exposure to endocrine-disrupting chemicals and their health effects.

The chemicals strategy, part of the European Green Deal, is designed to be the foundation for the biggest update to Europe’s chemical regulations in more than a decade. The chemical strategy commits to a hazard identification for EDCs, including strict measures to prevent their use in consumer products. The strategy also calls for stricter data requirements for EDCs across all relevant legislation and to accelerate the development and adoption of better test methods. In a statement, the Endocrine Society praised the new strategy, and urged “further details and concrete actions” to protect public health.

Healio spoke with Barbara Demeneix, PhD, DSc, chair of the Endocrine Society’s EDC advisory group, about the latest push in Europe to assess EDCs, the risks of combination chemicals and how endocrinologists can become better advocates to rein in EDC use in the United States.

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Substances chimiques: la Commission pour une réforme d’ampleur

Mediapart
De Cédric Vallet

14/10/2020

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La Commission européenne a présenté mercredi une nouvelle stratégie vis-à-vis de la gestion des produits chimiques. Une « réforme majeure », clament des ONG, qui s’est imposée malgré de fortes résistances internes.

La Commission européenne a proposé ce mercredi 14 octobre des changements en profondeur dans la gestion des 140 000 substances chimiques mises sur le marché européen, dont 74 % peuvent s’avérer dangereuses pour la santé humaine ou l’environnement.

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De l’eau, oui, mais en bouteille ou au robinet ?

La Croix
De Sophie Viguier-Vinson

10/12/2020

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Si tout le monde s’accorde pour nous recommander de boire beaucoup d’eau, le débat devient plus vif quand il s’agit de choisir quelle eau. Écologie, pollution, économies, santé… Entre eau minérale et eau courante, tout ne se vaut pas. Cas de conscience.

J’adore mon eau minérale, son goût, ses bulles délicates. Je l’aime aussi plate pour le sport, ou bien dosée en magnésium pour l’humeur et la digestion à mes heures… Elle flatte mes papilles, contribue à préserver ma santé, car de fait, j’en bois plus ainsi, comme me l’a recommandé le médecin. « 1,5 litre par jour minimum », a-t-il insisté, pour être bien hydratée.

Sauf que chacune de mes bouteilles préférées rejoint la montagne de déchets à recycler, quand elle ne finit pas dans le fond encombré des océans. Je le sais, je les vois, je ne peux plus oublier leur poids dans le bilan carbone de la planète et sur la biodiversité, au point que l’amertume s’est infiltrée dans les molécules d’H₂O.

« En France, 25 millions de bouteilles en plastique sont utilisées chaque jour et 42 % ne sont pas recyclées en Europe », rappelle Marillys Macé, directrice générale du Centre d’information de l’eau fondé par les distributeurs Veolia, Suez et Saur. De quoi gonfler mes scrupules et forcer le retour à la source domestique, celle du robinet. Sans hésitation ?

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Ammonium nitrate and iodine: a look back at the explosive history of two essential substances

The Conversation
From Barbara Demeneix

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The horrific explosion that devastated Beirut on August 4, 2020, has receded, but the physical damage and human distress persists. Reports indicate that fireworks were also stored in the same warehouse as the fertiliser and could sparked the larger, more deadly explosion of the fertilizer.

The two faces of ammonium nitrate

Nitrogen makes up 78% of the atmosphere and is chemically and biologically inert. However, in 1908 the chemist Fritz Haber discovered that nitrogen could be fixed chemically as ammonium nitrate. As a German patriot, Haber was also interested in Germany’s preparation for what would become World War I. A problem was that the methods Haber used could not be scaled up for industrial production. It was a fellow German, Carl Bosch, who perfected the industrialisation of the method in 1913, a year before the war’s start.

Haber and Bosch were both awarded Nobel prizes for their work – Haber in 1918 and Bosch in 1931. The prizes were instituted by Alfred Nobel, who financed the prizes thanks to his patents for the explosives dynamite and gelignite. Like other explosives, these comprise a molecular mix that releases energy suddenly, most often accompanied by the production of heat, light, gases, pressure and deafening sound.

In his Nobel acceptance speech, Haber acknowledged only that his discovery would help feed the world by improving soil fertility with ammonia. And there is no doubt that it did – populations have more than tripled since then. However, the speech did not mention his the main motivation for his work, Germany’s war effort. Haber also contributed to that effort with the production of chlorine gas. What is more, Haber almost certainly did not anticipate the implications of his discovery for fixing ammonia for its contribution to climate change.

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Is the Observed Decrease in Body Temperature During Industrialization Due to Thyroid Hormone-Dependent Thermoregulation Disruption?

Frontiers in Endocrinology
From Pieter Vancamp and Barbara Demeneix

@Pixabay

Protsiv et al. used three sets of data to demonstrate that human core body temperature had decreased by 0.03°C per decade since the industrial revolution in the US (1). They proposed that a 1.6% temperature drop over a period of almost 200 birth years had occurred. Anthropometrics, gender, or race were excluded as potential factors. The authors postulated that the principle contributor to this reduction was reduced inflammation, reflecting better, healthier environments and improved hygiene measures (1). Although hygiene has increased and hence reduced death from infectious disease, other factors in our environment have also changed significantly. Here we propose another plausible and potentially testable mechanism, that of the contribution of factors interfering with thyroid hormone (TH) metabolism.

TH is an essential physiological cue that acts at central and peripheral levels to affect internal temperature in endotherms (2). Humans strive to live at thermoneutral conditions, in which peripheral muscle metabolism generates sufficient heat as a by-product to maintain temperature without the need for additional heat-generating mechanisms (3). For us, the resting metabolic rate (RMR) is thus a crude proxy for core body temperature. TH directly affects the RMR by altering mitochondrial biogenesis and oxidative phosphorylation via TRα1, the principle TH receptor isoform in muscle (Figure 1) (4). TH fluctuations within the normal range alter the RMR in humans (5, 6), suggesting that subtle changes in TH homeostasis could have consequences for body temperature. Recent data indicate that TH also safeguards core body temperature at the central level. 

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How fossil fuel-derived pesticides and plastics harm health, biodiversity, and the climate

The Lancet Diabetes & Endocrinology
From Barbara Demeneix

@Pixabay

Three global challenges menace survival as we know it: climate change, loss of biodiversity, and chemical pollution (including endocrine-disrupting chemicals). These threats are more strongly interlinked than previously thought by their common origins in fossil fuels such as coal, oil, or gas, including that derived from fracking.

It is well established that accumulation of anthropogenic greenhouse gases (CO2, methane, and N2O) in the atmosphere is the main driver of climate change. However, policy makers and the general public need to better appreciate the links of each of these threats to life.
The foremost threats are chemical pollution, plastic pollution, and loss of biodiversity, as each is largely linked to the fossil fuel industry. The argument is that not only can these threats be averted, but also by reducing our dependence on fossil fuel usage we can simultaneously mitigate and eventually reverse the current climate crisis and improve environmental wellbeing and human health. If we are to embrace these economic transitions which are so urgently required, a deeper understanding of the interlinked mechanisms is needed.

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Tribune : Perturbateurs endocriniens: le niveau de protection actuel est-il illusoire?

Mediapart – Le Club
Par Les invités de Mediapart

« Il est temps que, face à la menace des perturbateurs endocriniens et au temps perdu du fait de la pression des lobbies, la politique européenne privilégie enfin la santé environnementale », alerte un collectif de chercheurs et de médecins au sujet de la contamination chimique de notre environnement et de nos organismes. Ils appellent à mettre en place le principe de précaution, « l’un des fondements de la législation européenne ».

La contamination chimique de notre environnement et de nos organismes est une composante majeure de la crise écologique actuelle, particulièrement par les perturbateurs endocriniens (PE). Dans le cadre du règlement « pesticides », l’Union Européenne a adopté une définition fin 2017, mais celle-ci permet-elle vraiment de protéger les populations ? Autrement dit, se contente-t-elle d’éliminer quelques molécules ou met-elle en oeuvre le principe de précaution pourtant l’un des fondements de la législation européenne ?

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Ce qui nous ronge le cerveau : enquête sur l’effondrement général du QI

Marianne 
Par Emmanuel Lemieux

© Pixabay

Selon Barbara Demeneix, spécialiste des perturbateurs endocriniens, tout concorde pour un effondrement massif de notre QI. Passage au scanner de ce qui nous grignote l’intelligence.

Elle porte un joli chapeau de paille et nous répond avec un délicieux accent anglais, Barbara Demeneix, endocrinologue au CNRS et ancienne codirectrice du labo Evolution des régulations endocriniennes du Muséum national d’Histoire naturelle. Mais cela atténue à peine l’état des lieux terrifiant qu’elle établit depuis des années. Celui de la chimie et des perturbateurs endocriniens qui sont, selon ses études et hypothèses, une menace certaine pour notre quotient intellectuel. L’effondrement de nos sociétés viendra peut-être par le cerveau. Et cela a déjà commencé. Interrompant notre entretien, elle rend d’autorité au garçon de café un peu décontenancé les innocentes pailles en polypropylène de nos Perrier-rondelle : les poisons plastifiés ne passeront pas par elle.

Les perturbateurs endocriniens, avec des molécules chimiques qui ont été multipliées par 300 depuis les années 70, colonisent notre quotidien, nos organismes et nos pensées. Les fœtus du XXIe siècle baignent désormais dans un liquide amniotique qui, si l’on force le trait, relève plus de la cuve d’usine de type Seveso que du lac de montagne niché dans une vallée préservée – alors que l’on recommande aux mamans de ne surtout pas prendre de médicaments. Les impacts sont encore mal connus, mais néanmoins inquiétants. Dans le liquide amniotique, on repère désormais le bisphénol qui a franchi sans problème la barrière placentaire.

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Contestado na Europa e nos EUA, agrotóxico que reduz QI de crianças é liberado no Brasil

RFI Brasil
Por Lúcia Müzell

Segundo especialistas, ele deixa traços nos alimentos e, no organismo humano, causa danos como distúrbios hormonais, deficiência mental irreversível nos fetos e diminuição de até 2,5 pontos de QI (quociente de inteligência) das crianças. O clorpirifós é um agrotóxico que surgiu para substituir o devastador DDT na agricultura e é usado há mais de 50 anos – mas é cada vez mais contestado pelos efeitos nocivos à saúde e ao meio ambiente.

O produto combate larvas e insetos e foi banido de oito países europeus. A sua licença para a utilização agrícola na União Europeia se aproxima do fim e o prazo, janeiro de 2020, levantou o debate sobre a pertinência de renovar a autorização. Segundo o jornal francês Le Monde, a Comissão Europeia estuda a possibilidade de não validar a permissão.

Uma das maiores especialistas em perturbadores hormonais do mundo, a pesquisadora Barbara Demeneix, do Laboratório de Evolução dos Reguladores Endócrinos de Paris, avalia que, se for concretizada, a medida já virá tarde.

“Nós esperamos muito que seja proibido na Europa, depois de tantos estudos não só sobre o impacto nas crianças, mas também no meio ambiente”, sustenta Demeneix. “Uma pesquisa incrível mostrou os efeitos desse químico nos peixes-corais. O estudo foi muito claro em demonstrar o quanto o clorpirifós afeta os hormônios da tireoide, portanto o desenvolvimento de todos os vertebrados. Está claro que há impactos não só no homem, como na biodiversidade.”

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Eye on France: Children clobbered by chlorpyrifos!

RFI English
Michael Fitzpatrick

After glyphosate, the cancer-inducing weedkiller, the French papers look at chlorpyrifos, a commonly used pesticide suspected of pillaging our children’s IQs.

Chlorpyrifos is a pesticide which has been sprayed on European farms for the past half century, despite a staggering weight of scientific evidence suggesting that exposure to the stuff dramatically reduces the IQ of children. It also kills greenfly and caterpillars, which is why farmers like it so much.

Unfortunately, chlorpyrifos survives on our spinach leaves, lettuce, potatoes and oranges. It is to be found in our kids’ urine, and in the umbilical cords of pregnant women.  Since 1965, evidence has been accumulating that this neurotoxin causes irreversible brain damage in youngsters, knocking 13 million points off the IQ of Europe’s children every year, and causing nearly 60,000 cases of mental deficiency.

 

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Chlorpyrifos – Barbara Demeneix: “Detrimental effects on IQ”

Investigative Reporting Denmark
Stéphane Horel

©Investigative Reporting Denmark 

The Cross-border investigation on chlorpyrifos was initiated by Investigative Reporting Denmark and Danwatch, and made in collaboration with journalists from Knack in Belgium, Le Monde in France, Dagbladet in Norway, Newsweek in Poland, Ostro in Slovenia, El Confidential in Spain and The Midwest Center for Investigative Reporting in US. The investigation was supported by Journalismfund.eu.

Barbara Demeneix : “Detrimental effects on IQ”

“The scientific evidence clearly shows that prenatal exposure to chlorpyrifos has detrimental effects on IQ and brain cortex thickness. Chlorpyrifos is toxic for the central nervous system, i.e. neurotoxic, and it is an endocrine disruptor, notably of thyroid signalling. Chlorpyrifos can thus interfere with brain development.”

“In 2012, it was shown that brain cortex thickness is significantly reduced as a result of prenatal chlorpyrifos exposure. Recently, French researcher Vincent Laudet has demonstrated unequivocally that chlorpyrifos is a thyroid disrupting chemicals. One can wonder why it has not already been banned.”

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Is air pollution ruining your memory?

The Telegraph
By Harry de Quetteville

©Pixabay

I have a little gadget on my kitchen shelf. It measures levels of a particle known as PM2.5 – the tiny, invisible, sooty bits of combustion that are key culprits in the air pollution health crisis.

Produced by diesel and petrol fumes, log burners and even conventional ovens, PM2.5s are small enough to make it deep into the lungs and from there into the bloodstream. They’ve been linked to diseases ranging from cancer to high blood pressure and, as the World Health Organisation (WHO) puts it, “increased mortality or morbidity”.

When I pop two slices of bread into the toaster for my six and four year old, the monitor goes bananas. The PM count in micrograms per cubic metre races up from 9 or 10 into the hundreds.

« “There’s so much data on air pollution on working memory and your capacity to think. […] It’s not just traffic. All volatile compounds, like pesticides found in rural areas, can be included.” Barbara Demeneix

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Chlorpyrifos : les dangers ignorés d’un pesticide toxique

Le Monde
Par Stéphane Horel

C’est une famille de pesticides qui vole en moyenne 2,5 points de quotient intellectuel (QI) à chaque enfant européen. Son principal représentant, comme beaucoup de produits chimiques, porte un nom compliqué qui lui garantit le confort d’un certain anonymat. Pourtant, il contamine notre vie quotidienne. D’abord pulvérisé sur les cultures pour éliminer pucerons ou chenilles, le chlorpyrifos poursuit son existence sous la forme de traces dans les oranges, les pommes, la laitue, l’urine des enfants et le cordon ombilical des femmes enceintes.

Au fil d’un demi-siècle de pulvérisation, les données scientifiques se sont accumulées sur les effets nocifs de cet insecticide. Censé remplacer le DDT et ses effets délétères en 1965, le produit de la firme américaine Dow endommage en fait le cerveau des enfants de manière irréversible.

 

« On peut se demander pourquoi il n’a pas déjà été interdit. Le chlorpyrifos est toxique pour le système nerveux central, c’est-à-dire neurotoxique, et c’est un perturbateur endocrinien qui agit notamment sur la signalisation thyroïdienne. Il peut donc interférer avec le développement du cerveau. ».   Barbara Demeneix

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