EDC-MixRisk project has started its final year. It is time to take stock on what has been accomplished in the project so far as well as to take a look at the progress and key results at this stage.

The overall concept underpinning EDC-MixRisk is that early life exposure to EDC mixtures induces changes in the organism that underlie increased susceptibility to diseases during the entire life span. Three health domains are addressed in the project (growth and metabolism, neurodevelopment, and sexual development).

In the epidemiological module, mixtures of EDCs are identified, exposure to which is associated to adverse health outcomes in the three domains. These mixtures are subsequently composed and tested in different experimental systems relevant for the respective health outcomes. To test mixtures that are composed based on epidemiological data is a novel strategy to tackle the mixture issue. The experimental data are then on one hand, integrated into the risk assessment methods developed in the project, and, on the other hand, used to refine the biostatistical analyses. Two sets of mixtures have been established for metabolism and growth (G), neurodevelopment (N) and sexual development (S). The mixtures are based on data from the Swedish mother-child pregnancy cohort SELMA.

In the experimental module, mixtures 0 and 1 are tested in various animal and cell models to identify molecular actions of the mixtures that could underlie their adversity. Results obtained in mice, tadpoles, zebrafish, and cell models show that mixtures 0 for all the health domains induce negative effects on the molecular, cellular, and organismal level. In some of the assays, effects were observed even at the lowest concentrations tested, which correspond to the actual levels of the SELMA mothers.

Interestingly, the mixtures disrupted common signalling pathways in cell and in animal models, which enabled us to link the molecular effects to adverse outcomes such as increased adipose tissue, behavioural changes, and disruption of sexual organ development. Selected single chemicals were also tested and their effects compared to the mixtures. In most cases, the single compounds did not have an effect at concentrations comparable to the mixtures.

An important part of the project is the improvement of the regulatory risk assessment of mixtures as well as science-to-policy interaction. Three different novel mixture risk assessment methods have been established and are now being elaborated on by conducting case studies using EDC-MixRisk and published data.

The EDC-MixRisk approach of identifying EDC mixtures associated with adverse health outcomes in a pregnancy cohort, preparing artificial mixtures of the bad actors for toxicological testing and using the experimental data for risk assessment is a novel approach and one of the major outcomes of the project. More specifically, this proof-of-concept, will enable more systematic integration of epidemiological and experimental evidence into mixture risk assessment strategies.

By applying the novel approach, which is based on real life exposure data, we could find a higher rate of pregnant women at risk when compared with more traditional models of additivity. This adds to the evidence that cocktail effects of manmade chemicals are not properly taken into account in risk assessment and management of chemicals. More systematic approaches are needed, both in terms of science and regulations. The improved testing strategies and risk assessment methodologies developed in the project are important for the regulatory processes to protect public health and to avoid hazardous chemicals, whether they come in mixtures or as single substances.

Read the full summary of the project progress here.


Five EU-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 chemical mixtures and combined exposure. The projects have engaged into an exchange between the consortia, European Commission Services and relevant EU Agencies in order to identify remaining gaps in mixture research and policy. As a result of this effort, a joint workshop entitled “Advancing the Assessment of Chemical Mixtures and their Risks for Human Health and the Environment” was organized at Joint Research Centre (JRC), Ispra, 29-30 May 2018. The workshop brought together around 60 experts working in the field of chemical mixtures.

Photo: © European Union, 2018

The workshop provided a great forum to discuss the latest advancements in science as well as research and policy needs in order to make progress in mixture risk assessment and management. The topics of the workshop included hazard and exposure assessment, data and tools, and risk analysis and governance. The international horizons and developments outside the EU were covered by keynote speakers from USA, Japan and OECD.

Although much progress has been achieved over the recent years, the participants stated that it is evident that more needs to be done to better address the combined exposure of multiple chemicals, both in terms of intentional (e.g. pesticides and cosmetic products) and unintentional mixtures (e.g. contaminants via air). One of the major gaps continues to be the lack and availability of data. The Information Platform for Chemical Monitoring, IPCHEM is addressing the gap for chemical monitoring data. However, another big challenge remains in the accessibility and quality of data on (eco)toxicological properties and on the types of use of chemicals.

In the group and plenary discussions, ideas were brought up on improving governance aspects to better protect public health and environment from hazardous chemical mixtures. The proposals from many project participants included e.g. encouraging policymakers to look into the opportunities of establishing clear legal mandates for mixture risk assessment within EU chemicals and environmental legislation and across the regulatory silos. It was also suggested that “protection goals” should be established for human health, applying the idea and concept from the Water Framework Directive which requires good chemical and ecological status for European water bodies. For humans, similar type of “protection goals” could be set for good chemical and health status. Furthermore, it was raised that there is a need for developing uniform principles and harmonised approaches for performing human and environmental mixture risk assessments. In practice, also procedures should be piloted and put in place to enable more holistic and systematic mixture risk assessments, across regulatory bodies and sectors. It was concluded that interdisciplinary and international collaboration as well as dialogue between scientists, regulators and policy-makers are essential to make progress in the mixture efforts.

The workshop outcome and future research needs will be published later in 2018.

JRC has published recently a news item on chemical mixtures and safety of combined exposures: https://ec.europa.eu/jrc/en/news/chemical-mixtures-safety

JRC has also published a related Policy Brief: “Something from nothing? Ensuring the safety of chemical mixtures”:
https://ec.europa.eu/jrc/en/publication/something-nothing-ensuring-safety-chemical-mixtures


The EHESP School of Public Health and the IRSET Research institute for environmental and occupational health organized the 5th European Doctoral College on Environment and Health (EDCEH) in Rennes, France, 4-6 June 2018.

EDC-MixRisk was represented in the meeting by Dr. Anastasia Repouskou from the School of Health Sciences, National and Kapodistrian University of Athens. She presented in the meeting their recent study on the effects of gestational exposure to a mixture of four phthalates (mixture S) on the reproductive health of mice. Mouse is one of the experimental models used in EDC-MixRisk to study the health effects of chemical mixtures.

Phthalates are repeatedly detected in humans, raising thus significant concerns due to the constant exposure and their endocrine disruptive properties. They are widely used as plasticizers in the manufacture of hundreds of commercial products.

The results of the study indicated that in utero exposure of experimental animals (mice) to a mixture of phthalates administered at epidemiologically-defined concentrations and simulating real-life human exposure levels, leads to long-term reproductive defects, particularly of male offspring. The title of Dr. Reposkou’s abstract was “Reproductive impact of gestational exposure to an epidemiologically-defined phthalate mixture in prepubertal and adult mice”.

The meeting offered a great opportunity for networking and insight into important topics regarding endocrine disruptors (EDs), such as definition of EDs within the regulatory context, emerging approaches for assessing the exposure to EDs, models and (non-)standard tests for endocrine disruption and innovative methods and predictive tools to investigate endocrine disruption.

Click here for more information about the meeting.


The conference entitled ”Aiming for a Safe Chemical Environment: New Frontiers in the Comprehension of Endocrine Disrupting Chemicals Exposure, Effects and Specific Risk Assessment Requirements” took place in Les Diablerets, June 3-8, 2018. It was the 11th Gordon Research Conference on Environmental Endocrine Disruptors.

EDC-MixRisk was represented in the meeting by Prof. Carl-Gustaf Bornehag from Karlstad University who gave a presentation in the meeting about a novel approach, a proof-of-concept, which has been developed within the project for the risk assessment of chemical mixtures. The title of his presentation was “A novel approach for risk assessment of chemical mixtures – Linking data from population based epidemiology and experimental toxicology in the EDC-MixRisk study

Also several other EDC-MixRisk researchers were present at the meeting to discuss the topical aspects and latest scientific advances in research of Environmental Endocrine Disruptors (EEDs).

The meeting provided an overview of:

  • EED effects in wildlife and laboratory animal models and life-span effects in the context of human exposure
  • review of our current understanding of EED effects and mechanisms of action, including at low-doses
  • updated state of the science and discussion on specific issues, such as mixture effects, perinatal imprinting and novel paradigms e.g. on microbiome’s role and trans-generational effects
  • key issues related to incorporating the results of laboratory, field and human studies in the process of EED risk assessment.

For more information about the conference:
https://www.grc.org/environmental-endocrine-disruptors-conference/2018/


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.