Comprendre la perturbation endocrinienne

“Émission du Labo”, enregistrée en public au Lieu Unique, Nantes, le 14 mai 2019

Les sources d’exposition sont nombreuses et difficiles à maîtriser, tout comme leurs conséquences biologiques.

Historiquement, les perturbateurs endocriniens ont commencé à attirer l’attention des chercheur·euses dès les années 1950. Mais c’est l’affaire du distilbène qui, dans les années 1970, a fait exploser le sujet sur la scène scientifique et médiatique, alors même que le terme de “perturbateur endocrinien” n’était pas encore utilisé.

Aujourd’hui, c’est un enjeu majeur de santé publique, pour nous qui sommes vivants, mais aussi pour les générations futures, celles qui n’ont pas encore vu le jour. Référence.

Le Distilbène DES, en savoir plus

Chemicals, pesticides, microplastics added to supermarket food

The Honest Supermarket – What’s Really in Our Food ?

Can we trust our supermarkets to tell us the truth about what we are buying and how it was produced ?

For every pound we spend on food shopping, 77p goes to the supermarkets, giving them a huge influence over what we eat. Do their profits come first ?

In an experiment to discover the hidden truths about our everyday foods, Horizon has built the first ever truly ‘honest supermarket’. Drawing on the latest scientific research and leading experts from across the UK, the team have built a supermarket where the products are labelled with the real story of how they are produced and their effect on us and the environment. We invite the British public to come in and discover the truth about their favourite foods. And in our on-site lab, new scientific discoveries reveal the food facts the supermarkets aren’t telling you.

Presented by Dr Hannah Fry and dietician Priya Tew, The Honest Supermarket takes a cold hard look at what’s really going on with the food we eat. From new research that reveals you’re likely to be ingesting plastic particles along with your bottled water to the lab tests that uncover the disturbing truth about just how old your ‘fresh’ supermarket fish really is…

You’ll never look at the food on your supermarket shelves in the same way again says BBC2 Horizon, Jul 2019.

Prenatal exposure to chemicals in personal care products linked to earlier puberty in girls

Association of phthalates, parabens and phenols found in personal care products with pubertal timing in girls and boys

Girls exposed to chemicals commonly found in toothpaste, makeup, soap and other personal care products before birth may hit puberty earlier, according to a new longitudinal study led by researchers at UC Berkeley (see press release).

2019 Study Abstract

STUDY QUESTION
Are in-utero or peripubertal exposures to phthalates, parabens and other phenols found in personal care products associated with timing of pubertal onset in boys and girls?

SUMMARY ANSWER
We found some associations of altered pubertal timing in girls, but little evidence in boys.

WHAT IS KNOWN ALREADY
Certain chemicals in personal care and consumer products, including low molecular weight phthalates, parabens and phenols, or their precursors, are associated with altered pubertal timing in animal studies.

STUDY DESIGN, SIZE, DURATION
Data were from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) longitudinal cohort study which followed 338 children in the Salinas Valley, California, from before birth to adolescence.

PARTICIPANTS/MATERIALS, SETTING, METHODS
Pregnant women were enrolled in 1999–2000. Mothers were mostly Latina, living below the federal poverty threshold and without a high school diploma. We measured concentrations of three phthalate metabolites (monoethyl phthalate [MEP], mono-n-butyl phthalate and mono-isobutyl phthalate), methyl and propyl paraben and four other phenols (triclosan, benzophenone-3 and 2,4- and 2,5-dichlorophenol) in urine collected from mothers during pregnancy and from children at age 9. Pubertal timing was assessed among 179 girls and 159 boys every 9 months between ages 9 and 13 using clinical Tanner staging. Accelerated failure time models were used to obtain mean shifts of pubertal timing associated with concentrations of prenatal and peripubertal biomarkers.

MAIN RESULTS AND THE ROLE OF CHANCE
In girls, we observed earlier onset of pubic hair development with prenatal urinary MEP concentrations and earlier menarche with prenatal triclosan and 2,4-dichlorophenol concentrations. Regarding peripubertal biomarkers, we observed: earlier breast development, pubic hair development and menarche with methyl paraben; earlier menarche with propyl paraben; and later pubic hair development with 2,5-dichlorophenol. In boys, we observed no associations with prenatal urinary biomarker concentrations and only one association with peripubertal concentrations: earlier genital development with propyl paraben.

LIMITATIONS, REASONS FOR CAUTION
These chemicals are quickly metabolized and one to two urinary measurements per developmental point may not accurately reflect usual exposure. Associations of peripubertal measurements with parabens may reflect reverse causality: children going through puberty early may be more likely to use personal care products. The study population was limited to Latino children of low socioeconomic status living in a farmworker community and may not be widely generalizable.

WIDER IMPLICATIONS OF THE FINDINGS
This study contributes to a growing literature that suggests that exposure to certain endocrine disrupting chemicals may impact timing of puberty in children.

STUDY FUNDING/COMPETING INTEREST(S)
This study was funded by the National Institute of Environmental Health Sciences and the US Environmental Protection Agency. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER
N/A.

Overview of known plastic packaging-associated chemicals and their hazards

Which hazardous chemicals are associated with plastic packaging?

The use of plastic packaging is increasing globally, causing environmental and human health concerns. In 2015 annual plastic production was 380Mt, of which about 40 per cent was used in packaging, with the majority being used in food packaging.

The 906 substances which are most likely to be associated with plastic packaging have been published on the Data Commons websiteAt least 148 of the 906 chemicals most likely to be associated with plastic packaging were identified as particularly hazardous based on several harmonized hazard data sources, and 35 of the chemicals listed are regarded as endocrine disrupting chemicals (EDCs), CHEM Trust reports.

2018 Study Highlights

  • Database of Chemicals associated with Plastic Packaging (CPPdb) is presented.
  • CPPdb contains chemicals used in manufacturing and/or present in final articles.
  • 906 chemicals identified as likely, 3377 chemicals as possibly associated.
  • Hazard data: CLP classifications, EDC, PBT, vPvB identifications explored.
  • Data gaps concerning both the use and toxicity of numerous substances identified.

Abstract

Global plastics production has reached 380 million metric tons in 2015, with around 40% used for packaging. Plastic packaging is diverse and made of multiple polymers and numerous additives, along with other components, such as adhesives or coatings. Further, packaging can contain residues from substances used during manufacturing, such as solvents, along with non-intentionally added substances (NIAS), such as impurities, oligomers, or degradation products. To characterize risks from chemicals potentially released during manufacturing, use, disposal, and/or recycling of packaging, comprehensive information on all chemicals involved is needed. Here, we present a database of Chemicals associated with Plastic Packaging (CPPdb), which includes chemicals used during manufacturing and/or present in final packaging articles. The CPPdb lists 906 chemicals likely associated with plastic packaging and 3377 substances that are possibly associated. Of the 906 chemicals likely associated with plastic packaging, 63 rank highest for human health hazards and 68 for environmental hazards according to the harmonized hazard classifications assigned by the European Chemicals Agency within the Classification, Labeling and Packaging (CLP) regulation implementing the United Nations’ Globally Harmonized System (GHS). Further, 7 of the 906 substances are classified in the European Union as persistent, bioaccumulative, and toxic (PBT), or very persistent, very bioaccumulative (vPvB), and 15 as endocrine disrupting chemicals (EDC). Thirty-four of the 906 chemicals are also recognized as EDC or potential EDC in the recent EDC report by the United Nations Environment Programme. The identified hazardous chemicals are used in plastics as monomers, intermediates, solvents, surfactants, plasticizers, stabilizers, biocides, flame retardants, accelerators, and colorants, among other functions. Our work was challenged by a lack of transparency and incompleteness of publicly available information on both the use and toxicity of numerous substances. The most hazardous chemicals identified here should be assessed in detail as potential candidates for substitution.

60 MiNueTs Toxic

UCSF Program on Reproductive Health and the Environment, 2017

Video published on 18 Apr 2019 by the UCSF Program on Reproductive Health and the Environment.

The University of California San Francisco (UCSF) Program on Reproductive Health and the Environment (PRHE)’s mission is to create a healthier environment for human reproduction and development through advancing scientific inquiry, clinical care and health policies that prevent exposures to harmful chemicals in our environment.

More Information

Adult and Prenatal Chemical Exposures

Breast Cancer Prevention Partners, with Tracey Woodruff, Ph.D., Mar 2019

  • How am I exposed to chemicals?
  • What are prenatal exposures?
  • How can I reduce my own personal exposures?
  • What more can I do to help make a change?

Featuring BCPP Science Advisory Panel member Tracey Woodruff, Ph.D., Director of the Program on Reproductive Health and the Environment, University of California, San Francisco, Professor in the Department of Obstetrics, Gynecology, and Reproductive Sciences and Philip R. Lee Institute for Health Policy Studies at UCSF

Effect of environmental and pharmaceutical exposures on fetal testis development and function

A systematic review of human experimental data, 2019

Abstract

BACKGROUND
Overall, the incidence of male reproductive disorders has increased in recent decades. Testicular development during fetal life is crucial for subsequent male reproductive function. Non-genomic factors such as environmental chemicals, pharmaceuticals and lifestyle have been proposed to impact on human fetal testicular development resulting in subsequent effects on male reproductive health. Whilst experimental studies using animal models have provided support for this hypothesis, more recently a number of experimental studies using human tissues and cells have begun to translate these findings to determine direct human relevance.

OBJECTIVE AND RATIONALE
The objective of this systematic review was to provide a comprehensive description of the evidence for effects of prenatal exposure(s) on human fetal testis development and function. We present the effects of environmental, pharmaceutical and lifestyle factors in experimental systems involving exposure of human fetal testis tissues and cells. Comparison is made with existing epidemiological data primarily derived from a recent meta-analysis.

SEARCH METHODS
For identification of experimental studies, PubMed and EMBASE were searched for articles published in English between 01/01/1966 and 13/07/2018 using search terms including ‘endocrine disruptor’, ‘human’, ‘fetal’, ‘testis’, ‘germ cells’, ‘testosterone’ and related search terms. Abstracts were screened for selection of full-text articles for further interrogation. Epidemiological studies involving exposure to the same agents were extracted from a recent systematic review and meta-analysis. Additional studies were identified through screening of bibliographies of full-texts of articles identified through the initial searches.

OUTCOMES
A total of 25 experimental studies and 44 epidemiological studies were included. Consistent effects of analgesic and phthalate exposure on human fetal germ cell development are demonstrated in experimental models, correlating with evidence from epidemiological studies and animal models. Furthermore, analgesic-induced reduction in fetal testosterone production, which predisposes to the development of male reproductive disorders, has been reported in studies involving human tissues, which also supports data from animal and epidemiological studies. However, whilst reduced testosterone production has been demonstrated in animal studies following exposure(s) to a variety of environmental chemicals including phthalates and bisphenol A, these effects are not reproduced in experimental approaches using human fetal testis tissues. Image credit academic.oup.

WIDER IMPLICATIONS
Direct experimental evidence for effects of prenatal exposure(s) on human fetal testis development and function exists. However, for many exposures the data is limited. The increasing use of human-relevant models systems in which to determine the effects of environmental exposure(s) (including mixed exposures) on development and function of human tissues should form an important part of the process for assessment of such exposures by regulatory bodies to take account of animal-human differences in susceptibility.

Prenatal and childhood exposure to phthalates and motor skills at age 11 years

Using Lipstick, Moisturizers During Pregnancy Linked To Motor Skill Deficiencies In Kids

2019 Study Highlights

  • Prenatal exposure to certain phthalates was associated with lower motor BOT-2 scores measured at 11 years of age among girls.
  • Postnatal exposure to certain phthalates was associated with lower motor proficiency among boys measured at 11 years of age.
  • The association between MEP measured at age 3 and motor performance at age 11 was different among girls and boys.

Abstract

Background
Previous reports suggest that prenatal phthalate exposure is associated with lower scores on measures of motor skills in infants and toddlers. Whether these associations persist into later childhood or preadolescence has not been studied.

Methods
In a follow up study of 209 inner-city mothers and their children the concentrations of mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), monoisobutyl phthalate (MiBP), monomethyl phthalate (MEP), mono-carboxy-isooctyl phthalate (MCOP), and four di-2-ethylhexyl phthalate metabolites (ΣDEHP) were measured in spot urine sample collected from the women in late pregnancy and from their children at ages 3, 5, and 7 years. The Bruininks-Oseretsky Test of Motor Proficiency short form (BOT-2) was administered at child age 11 to assess gross and fine motor skills.

Results
The total number of children included in the study was 209. Of the 209 children, 116(55.5%) were girls and 93 were (45%) boys. Among girls, prenatal MnBP(b=−2.09; 95%CI: [−3.43, −0.75]), MBzP (b=−1.14; [95%CI: −2.13, −0.14]), and MiBP(b=−1.36; 95%CI: [−2.51, −0.21] and MEP(b=−1.23 [95%CI: −2.36, −0.11]) were associated with lower total BOT-2 composite score. MnBP (b= –1.43; 95% CI: [–2.44, –0.42]) was associated with lower fine motor scores and MiBP(b = –0.56; 95% CI: [–1.12, –0.01]) and MEP (b = –0.60; 95% CI: [–1.14, −0.06])was associated with lower gross motor scores. Among boys, prenatal MBzP (b = –0.79; 95% CI: [–1.40, −0.19]) was associated with lower fine motor composite score.

The associations between MEP measured at age 3 and the BOT-2 gross motor, fine motor and total motor score differed by sex. In boys, there was an inverse association between ΣDEHP metabolites measured in childhood at ages 3 (b = –1.30; 95% CI: [–2.34, −0.26]) and 7 years (b = –0.96; 95% CI: [–1.79, −0.13]), and BOT-2 fine motor composite scores.

Conclusions
Higher prenatal exposure to specific phthalates was associated with lower motor function among 11- year old girls while higher postnatal exposure to ΣDEHP metabolites was associated with lower scores among boys. As lower scores on measures of motor development have been associated with more problems in cognitive, socioemotional functioning and behavior, the findings of this study have implications related to overall child development.

Research communication. Press release. Image mamans.femmesdaujourdhui.be.

Do Harmful Chemicals in Health and Beauty Products Make Uterine Fibroids Grow ?

Phthalates exposure and uterine fibroid burden among women undergoing surgical treatment for fibroids: a preliminary study

A pilot study published in the journal Fertility and Sterility suggests that exposure to certain harmful chemicals called phthalates may lead to an increased burden of fibroids, uterine tumors that can cause heavy bleeding, pain, infertility, and other serious reproductive problems.

2019 Study Abstract

Objectives
To examine the association between phthalate exposure and two measures of uterine fibroid burden: diameter of largest fibroid and uterine volume.

Design
Pilot, cross-sectional study.

Setting
Academic medical center.

Patient(s)
Fifty-seven premenopausal women undergoing either hysterectomy or myomectomy for fibroids.

Intervention(s)
None.

Main Outcome Measure(s)
The diameter of the largest fibroid and uterine dimensions were abstracted from medical records. Spot urine samples were analyzed for 14 phthalate biomarkers using mass spectrometry. We estimated associations between fibroid outcomes and individual phthalate metabolites, sum of di(2-ethylhexyl) phthalate metabolites (∑DEHP), and a weighted sum of anti-androgenic phthalate metabolites (∑AA Phthalates) using linear regression, adjusting for age, race/ethnicity, and body mass index. Fibroid outcomes were also examined dichotomously (divided at the median) using logistic regression.

Results
Most women were of black ethnicity, overweight or obese, and college educated. In multivariable models, higher levels of mono-hydroxyisobutyl phthalate, monocarboxyoctyl phthalate, monocarboxynonyl phthalate, mono(2-ethylhexyl) phthalate, mono(2-ethyl-5-hydroxyhexyl phthalate) (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), ∑DEHP, and ∑AA Phthalates were positively associated with uterine volume. Associations were most pronounced for individual DEHP metabolites (MEHHP, MEOHP, MECPP), ∑DEHP, and ∑AA Phthalates. For example, a doubling in ∑DEHP and ∑AA Phthalates was associated with 33.2% (95% confidence interval 6.6–66.5) and 26.8% (95% confidence interval 2.2–57.4) increase in uterine volume, respectively. There were few associations between phthalate biomarkers and fibroid size.

Conclusions
Exposure to some phthalate biomarkers was positively associated with uterine volume, which further supports the hypothesis that phthalate exposures may be associated with fibroid outcomes. Additional studies are needed to confirm these relationships.

The George Washington University press release.

Components of plastic : experimental studies in animals and relevance for human health

You are what you eat, and drink

Abstract

Components used in plastics, such as phthalates, bisphenol A (BPA), polybrominated diphenyl ethers (PBDE) and tetrabromobisphenol A (TBBPA), are detected in humans. In addition to their utility in plastics, an inadvertent characteristic of these chemicals is the ability to alter the endocrine system. Phthalates function as anti-androgens while the main action attributed to BPA is oestrogen-like activity. PBDE and TBBPA have been shown to disrupt thyroid hormone homeostasis while PBDEs also exhibit anti-androgen action. Experimental investigations in animals indicate a wide variety of effects associated with exposure to these compounds, causing concern regarding potential risk to human health. For example, the spectrum of effects following perinatal exposure of male rats to phthalates has remarkable similarities to the testicular dysgenesis syndrome in humans. Concentrations of BPA in the foetal mouse within the range of unconjugated BPA levels observed in human foetal blood have produced effects in animal experiments. Finally, thyroid hormones are essential for normal neurological development and reproductive function. Human body burdens of these chemicals are detected with high prevalence, and concentrations in young children, a group particularly sensitive to exogenous insults, are typically higher, indicating the need to decrease exposure to these compounds.

General Conclusions

Exposure of humans to pharmaceuticals is deliberate, with the intention of achieving a desired effect. Development and testing of medications involves a series of evaluations culminating in human clinical trials before marketing is approved. This is quite different from the situation with chemicals, whose presence in biota and humans is inadvertent. In the field of toxicology, information regarding potential human health effects is mainly derived from experimental studies and, when available, from epidemiological studies. Difficulties are not only encountered with extrapolation from animal models to humans, but epidemiological studies are also thwarted by drawbacks such as controlling for confounding factors. In particular, subjects are exposed to an assortment of chemicals on a daily basis and, often, lack of data regarding the extent of exposure at what may have been the critical time frame. One of the goals of toxicology is to identify effects in animal models with the aim to lower the risks of negatively impacting human health. Implicit in this task is that toxicological data, derived from animal studies indicating a potential for adverse effects, serve as a basis to limit exposure before effects appear or are confirmed in humans. The evidence from animal studies on single exposures to the chemicals discussed here suggests the potential for risk to human health. Moreover, data derived from co-exposure studies support the contention that the assortment of chemicals to which we are exposed on a daily basis increases the likelihood of health effects. The high prevalence of body burdens of these chemicals and simultaneous exposure to a number of substances, in conjunction with the fact that the highest concentrations have been demonstrated in the developing young, a sensitive subpopulation of society, indicate the need to decrease the exposure to these compounds.

Read the full study (free access) on NCBI PubMed, 2009 Jul 27.