To express concern and raise awareness on hazardous chemical mixtures and combined exposure, the Coordinators and representatives of several EC funded research projects, EDC-MixRisk, EuroMix, EU-ToxRisk, HBM4EU, SOLUTIONS, have sent a position paper (17 April 2018) to Director‐Generals of DG Environment, DG Research and Innovation and DG Health and Food Safety.

The position paper entitled “Preventing risks for people and environment from hazardous chemical mixtures” calls for action, taking benefit from the stepwise translation of the science i.e., employment of already existing  as well as development of new approaches, methodologies and tools. It proposes 12 key actions and recommendations to help better address combined effects and overcome remaining gaps in chemical mixture research and policy making. It also provides some feedback and ideas from research projects’ perspective to the preparations of the next Framework Programme, Horizon Europe.

 

Researchers and stakeholders agreeing with the key messages have the opportunity to support the initiative and co-sign the position paper (until 31 May 2018).

Link to the Position Paper: Position paper 180417 for the EC

Link to the co-signing form: https://goo.gl/forms/aORWa3FtxgpGth3o2


Five EC funded H2020 and FP7 research projects i.e. EDC-MixRisk, EuroMix, EU-ToxRisk, HBM4EU and SOLUTIONS, are working together to address different aspects of the impacts of mixtures on human health and the environment, including also research activities at the European Food Safety Authority (EFSA) and the Joint Research Centre (JRC). Through this collaboration, synergies, knowledge exchange and the ability to exchange and use methods and data will be promoted.

A joint workshop ‘Advancing the Assessment of Chemical Mixtures and their Risks for Human Health and the Environment’ will be held 29-30 May 2018 at the Joint Research Centre in Ispra, Italy. The aim is to discuss the current state of knowledge as well as further elaborate and prioritise areas for future policy and research needs. The active participation of experts from EFSA, JRC, the European Environment Agency and Directorate General Environment, as well as Directorate General for Research and Innovation will ensure policy relevance of the discussions.

The topics of the workshop include hazard and exposure assessment, data and tools, and risk analysis and governance. The meeting will focus on setting the scene in terms of governance and policy frameworks as well as on advancement in research, knowledge and identification of gaps. Further research and policy needs in the field will be discussed and elaborated together with the workshop participants. Also, there will be an opportunity to learn about the international approaches from U.S., Japan and OECD work. The intention is to publish the outcome of this workshop in a scientific journal. The ultimate aim of the collaboration is to maximise the impact of the work on mixtures and to enhance chemical safety.

 


European Institute of Oncology, IEO, in Milan, and Prof. Giuseppe Testa’s group is one of the EDC-MixRisk partners working at the nexus of interdisciplinary collaboration. Dr. Testa’s group has expertise in molecular biology, bioinformatics and social science. Within the framework of the EDC-MixRisk project, they work together to produce cutting edge-understanding of the adverse neurodevelopmental effects of exposure to EDC mixtures, and furthermore, help translate the work into regulatory meaningful arguments.

Recently, their experimental biology and bioinformatics work has been focusing on evaluating the impact of the EDC mixture associated (by the epidemiological module) to adverse developmental outcomes. To this end, the group has employed in vitro cellular models, including both fetal primary neural stem cells and cortical organoids, a tridimensional system able to recapitulate the human brain development. After exposing these models to the mixture of chemicals, advanced molecular and computational biology techniques were used to identify the key perturbed molecular events. Among the top dysregulated hits, genes known to be associated to autism spectrum disorders were discovered.

The social scientific work, in turn, not only draws on the work of experimental and computational biologists, but integrates with it. In this way, IEO has been able to produce mappings of the EU chemical regulatory field (public engagement, EU stakeholders and EU chemical regulations) and pinpoint areas where input from the project’s results will be most useful to mitigate EDC exposure risks. “This enables us to come to a more nuanced interpretive understanding of the relations between EDC exposure risks, governance and real-life contexts”, Dr. Testa concludes. The work continues at several fronts to confirm results and also publish the findings.


Chemical substances are often regulated one by one within the EU, but it is not common for similar substances to be regulated in groups or take into account real-life exposure across sectors. The Swedish Government wants to address this gap and also considers that a system is needed that takes into account the fact that chemical substances can aggravate each other’s hazardous effects, known as ‘combination effects’ or ‘cocktail effects’.

The government has appointed Christina Rudén, Professor of Regulatory Toxicology and Ecotoxicology at Stockholm University, as a special investigator in an investigation that will propose strategies for taking into account cocktail effects in legislation regulating chemicals. Dr. Rudén is also partner and Work package Leader in EDC-MixRisk.

”I am grateful and happy to get the opportunity to work with this important and complex issue. I hope to be able to come up with clear recommendations on how to push this question further and thereby contribute to realizing the goal of a non-toxic environment”, expresses Christina Rudén.

Since 2010 the Government has been pursuing a special initiative to follow an action plan for a non-toxic environment. “It is high time we take a holistic approach to the large amounts of chemicals we are all exposed to in our everyday lives and produce a strategy for managing the risks. I am pleased that Christina Rudén, with her unique experience and expertise, has taken on this important assignment,” says Minister for the Environment Karolina Skog.

Link to the Government’s press release:
http://www.government.se/press-releases/2018/03/government-wants-to-investigate-cocktail-effects-of-chemicals/


EDC-MixRisk Annual Consortium Meeting will take place 22-24 May 2018 in Stockholm, Sweden. The programme will be packed with intense discussions preparing for the final year, as the project will end in spring 2019. The first day of the annual meeting will focus on discussing the key results and expected outcomes of the project, whereas the next two days will be dedicated to more in-depth discussions on the remaining tasks and plans for completing the work successfully.


Meet our EDC-MixRisk scientists working behind the scenes and learn more about their work. This time in line is Olle Söder who is Professor of Pediatrics and Head of Department of Women’s and Children’s Health, and of the pediatric endocrinology reproductive research unit, located at the Astrid Lindgren Children’s Hospital, Karolinska Institutet & University Hospital, Stockholm, Sweden. This is a translational research unit with a clinical division taking care of children with disorders of sex development (DSD) and other endocrine disorders. One of Prof. Söder’s major research interests is the impact of EDCs on testicular function.

Hi Olle – What are you and your research group studying in the project?

Our group is working on the effects of EDCs on androgen production. Many recent epidemiological studies have shown an increased incidence of disorders of sexual development (DSD) in boys, such as cryptorchidism, micropenis and hypospadias. The background to this phenomenon is unexplained but one hypothesis is that exposure to environmental EDCs may contribute by interfering with critical effects of androgens during male fetal development. This hypothesis has previously been studied in animal models but investigations in humans are sparse albeit necessary due to species differences.  Specifically, EDCs may affect the cascade of developmental events occurring in sexual differentiation of male fetuses by suppressing androgen production by fetal Leydig cells (FLC) or by disturbing proper organogenesis of external male genitalia. Such adverse action may ultimately result in DSD in newborn males.

We have exploited our unique access to human fetal tissue by pursuing studies in vitro with cells isolated from male fetal gonads and external genitalia. The aim of our part in EDC-MixRisk is to study EDC mixtures concerning their potential role in disturbances of male sexual development and, more specifically, in androgen production by human FLC and proliferation and differentiation of human fetal penial cells (hFPC) in vitro.

What have you discovered so far?

In EDC-MixRisk, we have the three health domains (growth and metabolism, neurodevelopment and sexual development). Our group has carried out studies with Mixture S0 to study the health effects on sexual development. The mixture reflects a “typically-measured” chemical mixture of EDCs in the SELMA mothers, and it thus corresponds to a real-life exposure situation.
We have found that “Mixture 0” at concentrations 10 and 100 nM significantly upregulated the expression of the important steroidogenic enzyme 5-alpha reductase 2 (SRD5A2) in human fetal penial cells (see fig.1).  This suggests that phthalates in “Mixture 0” may affect the levels of the potent androgen DHT, which is critical for normal organogenesis of male external genitalia in humans. Studies on the other mixture, “Mixture 1” and its effects on human fetal penial cells and human fetal Leydig cells are currently ongoing.

Figure 1: Effect of ”Mixture 0” on SRD5A2 in hFPC

What are the potential implications of your findings?

Our results suggest that “Mixture 0” has the potential to disturb the early fetal organogenesis of male external genitalia. This supports epidemiological evidence that environmental exposure of pregnant women to certain EDCs (e.g., phthalates) increases the risk for male fetuses to develop disorders of sexual development with genital abnormalities, such as micropenis, hypospadias and cryptorchidism. The ongoing analysis of “Mixture 1” will reveal if there is further support of the hypothesis that the development of male external genitalia in early gestation is sensitive to adverse actions of EDCs. The implications of such findings are of great importance as the results are derived from a model with human fetal tissue which is the direct target of EDCs in human fetal development.


Barbara Demeneix, Professor at the French National Museum of Natural History, is an internationally recognized expert on thyroid function and endocrine disruption. She is the work package leader of WP4 on identification of molecular initiating events in EDC-MixRisk project. Recently, she was interviewed for European Chemicals Agency’s newsletter on how chemicals can result in autism and IQ loss in developing children.

Endocrine disruptors are ubiquitous chemicals that interfere with body’s hormonal system, thereby producing harmful effects on human health including infertility, cancer and developmental disorders. These chemicals are released in our environment and can be found in daily products, such as in plastic bottles, toys, cosmetics, electronics, textile products and pesticides.

Exposure to these chemicals during foetal development poses a particular risk because the organ systems are still developing. Studies have shown that maternal levels of thyroid hormone during the first three months of pregnancy are determinant for the child’s brain development. Interference with the levels of maternal thyroid hormone will have a long-term impact on the formation and development of organs and neurons in the foetus. Many chemicals to which we are exposed can interfere with thyroid hormone signaling.

There has been a sharp increase in neurodevelopmental and metabolic diseases in modern western countries over the last decades. There is a biologically plausible mechanism between endocrine disruptors and their interference with thyroid hormone signaling: “Combining the facts that first, maternal hypothyroidism increases the risk of autism and second, that exposure to many chemicals reduces circulating thyroid hormones provides a strong case”, Professor Demeneix explains.

There is a need for rigourous testing as well as appropriate regulation of endocrine disrupting chemicals. The number of chemicals placed on the market is continuously increasing, so we are racing against time. However, you can try to limit your exposure to such chemicals. “Eating organic food can reduce your pesticide exposure. Also, you should air your home regularly and it is also very important to avoid smoking, either actively or passively, since this can alter thyroid hormone levels in early pregnancy,” Professor Demeneix advises. Further recommendations are developed in her latest book Toxic Cocktail.

 

Prof. Demeneix’s interview in ECHA’s Newsletter, People and Perspectives: How chemicals can result in autism and IQ loss in developing children, February 2018, Issue 1: https://newsletter.echa.europa.eu/home/-/newsletter/entry/how-chemicals-can-result-in-autism-and-iq-loss-in-developing-children

Her interview is also available on YouTube: https://www.youtube.com/watch?time_continue=1&v=LgPlKXBw4G4

Toxic Cocktail: how chemical pollution is poisoning our brains has been published by Oxford University Press in 2017: https://global.oup.com/academic/product/toxic-cocktail-9780190260934?cc=fr&lang=en&

 


The research performed in EDC-MixRisk helps to expand our knowledge on mixtures of endocrine disrupting chemicals. Meet our EDC-MixRisk scientists and hear their story on what they are doing and why it matters. This time in line is Carl-Gustaf Bornehag who is professor in Public Health Sciences and head of Public Health Sciences at Karlstad University, Sweden. He is an environmental epidemiologist with a major focus on health risks related to endocrine disrupting chemicals. He is also an adjunct professor at Icahn School of Medicine at Mount Sinai in New York.

 

Hi CG – What are you and your research group studying in the project?

Our focus is on population based epidemiological studies. Our main study – the SELMA study – includes around 2,000 mother-child pairs followed from early pregnancy and birth up to school age. In EDC-MixRisk, we are addressing a broad spectrum of exposures during early life (pregnancy and infancy period) that are significant for health and development during childhood in the three different health domains (sexual development, neurodevelopment, metabolism and growth). Our goal is to identify risk factors during sensitive periods of early life, e.g., environmental chemicals including endocrine disrupting chemicals, maternal stress, life styles etc. These risk factors can then be tested in controlled experimental studies in animal and cell models, which is our overall goal within the EDC-MixRisk project. Such interaction between epidemiology and experimental toxicology is a good platform for development of new and useful methods and tools for better risk assessment of harmful chemicals. The project brings together the experts from different disciplines and thus we have been able to develop good collaboration e.g. on risk assessment with Stockholm University and the group lead by professor Christina Ruden. We also have a major interest in exposure for mixtures of chemicals and have a deep collaboration with professor Chris Gennings and Icahn School of Medicine at Mount Sinai in New York which is also where I hold an adjunct professorship.

 

What preliminary results or interesting aspects have you discovered?

We have generated a lot of important data in the project. So far, some of the key results from our epidemiological efforts are:

– Prenatal exposure for phthalates (mainly from soft plastics) are associated to impaired sexual development in baby boys.

– Prenatal exposure for per fluorinated compounds (PFAAs) is associated to a lower birth weight with some differences between girls and boys.

– Prenatal exposure for mixtures of endocrine disrupting chemicals and the association to health effects in different domains.

– In terms of exposure, PVC flooring material is a strong source for human uptake of phthalates in pregnant women.

 

What are the potential implications of your findings and their usefulness for society?

I think that our epidemiological findings from the SELMA study may bring results of interest to the society, not least regarding the problem with mixture exposure where there is much more results to come but also clear needs for further research efforts and policy actions. However, I am more and more convinced that it is when we are putting our epidemiological efforts into a broader context – i.e., into an interaction with experimental studies and risk assessment activities- we will bring true societal impact and gains. Here we are just one part in a broader context, bringing one piece to the puzzle in the challenge to improve risk assessment of endocrine disrupting chemicals, mixtures and human health effects. And the main platform for this interaction is Swetox, collaboration between the Swedish universities, and of course all our international collaborators in this EC funded research project.

 


Exposure to EDCs is a potential threat to female reproductive health. Mixtures of chemicals can be found in serum of virtually every human being as biomonitoring studies have shown. Pregnant women are not an exception in this regard.

Levels of exposure to toxic chemicals and the resulting impacts on human health are largely determined by social as well as biological factors. Women, men, and children are exposed differently to toxic chemicals in daily life, including differences in the kinds of chemicals encountered as well as the level and frequency of such exposures. Furthermore, women and children vary in their physiological susceptibility to the effects of exposure to toxic chemicals.

EDC-MixRisk project addresses also the reproductive aspects to increase our understanding on the effects of chemical mixtures and gender on health. Dr. Pauliina Damdimopoulou’s group focuses on reproductive toxicology and the health effects of environmental endocrine active compounds. In EDC-MixRisk, the group will contribute to developing new methods and studying of health effects of chemical mixtures on women’s reproductive health.

Recently, the group has been working on the culture of a specific structure within the ovary, called a follicle. This follicle structure consists of supporting cells surrounding the growing egg. Previously, follicles have been successfully cultured using mouse tissue but challenges have remained in terms of human ovarian tissue.

The new model developed by Dr. Damdimopoulou’s group looks promising in applying the method to human tissue. Follicles in early stages of development are isolated from human ovaries that are obtained from Karolinska University Hospital Huddinge, and placed into a matrix to maintain their 3D structure. First, a cellulose matrix was tested but better success was achieved by using alginate which is a natural product of algae. The group is now working on improving the growth conditions to support follicle and egg development over a longer period of time.

A healthy human secondary follicle freshly isolated and ready for culture (Picture by Astrud Tuck)

The strength of this in vitro model is its direct relevance to humans. It also contributes to the replacement of animal-based methods and testing. Eventually, the research carried out by the group will increase our knowledge on how chemicals and chemical mixtures can affect women’s fertility. Furthermore, it is important to recognize the significant linkages between gender and chemicals.

 

For more information on the research team:
http://swetox.se/en/research/pauliina-damdimopoulou/


EDC-MixRisk project will organize a session “Integrating epidemiology and experimental toxicology to understand the risk of endocrine disrupting chemical mixtures on children” at the EUROTOX 2018 Congress which takes place in Brussels, 2-5 September 2018.

Endocrine disrupting chemicals (EDCs) and potential EDCs are found in various materials such as personal care products, pesticides, metals, additives or contaminants in food. A large body of evidence supports associations between exposure to chemicals and endocrine disrupting effects, leading to disorders in humans and wildlife. There is a need to handle EDCs according to the risks they pose, as single chemicals or as mixtures. This involves selection, refinement and development of tools for risk assessment of EDC mixtures to bring current procedures to a level where they can support proper risk management.

The session will give examples on how to determine and assess the risk for multiple adverse health outcomes based on molecular mechanisms involved, after early life exposure to complex mixtures of endocrine disrupting chemicals (EDCs). The session will present a new approach for identification of mixtures of EDCs that are associated with multiple adverse health outcomes in three health domains (growth and metabolism, neurodevelopment and sexual development) using epidemiological pregnancy cohort studies and via the application of novel and advanced bio-statistical methods to identify and prioritize chemical mixtures of concern. Experimental investigations in animal and cell models have thereafter been used in the project to test the mixtures in order to uncover molecular mechanisms underlying the effects seen in the epidemiological studies.

Furthermore, mixture effects on mesenchymal stem cell differentiation in relation to low birth weight and obesity later in life will be discussed at the session, as well as the transcriptomic and epigenomic profiling of human embryonic stem cells (hESC) during differentiation into neural progenitors exposed to EDC mixtures. The interdisciplinary approach, integrating epidemiology and experimental evidence, will facilitate assessment of risk and contribute to better risk management for EDCs and their mixtures.

EUROTOX 2018 homepage: http://www.eurotox-congress.com/2018/