EU-funded EDC-MixRisk Project Highlights Importance of Considering Combined Exposure to Multiple Chemicals
19 Sep 2018
We are exposed to multiple man-made chemicals from various sources. The EDC-MixRisk research project, coordinated by Karolinska Institutet, Swetox, emphasizes the need to address the effects of chemicals as mixtures in order not to underestimate the risks they pose. The current risk assessment paradigm seems to be falling short as it is largely based on considering one chemical at a time.
The EDC-MixRisk research project studies the effects of endocrine-disrupting chemicals (EDCs), focusing on EDC-mixtures and their effects on the developing foetus. Endocrine disruptors are chemicals that interfere with our hormonal system, and they have been linked to various diseases and disorders, e.g., infertility, cancer, obesity and impaired neurodevelopment.
EDCs are ubiquitous contaminants in our environment as they can be found in everyday products, such as in plastic bottles, toys, cosmetics, electronics, textiles and even in food as pesticide residues and as additives in food contact materials. The chemicals used in various products and materials leak and migrate to the environment reaching also us, human beings.
“To study effects of these chemicals in mixtures, we used real-life exposure data from the Swedish SELMA pregnancy cohort to see which chemicals the mothers and their children were exposed to, and identified EDC mixtures in prenatal urine and blood that were associated with adverse health outcomes in the children as a first step,” explains Carl-Gustaf Bornehag, Professor in Public Health Sciences at Karlstad University, Sweden.
“Based on the chemicals measured in mothers’ serum and urine, we established reference chemical mixtures in the project. They were then tested in experimental models for potential adverse effects in terms of growth and metabolism, neurodevelopment and sexual development,” he continues.
“We observed clear effects on behavior, metabolism, and development in cell and animal models,” says Joëlle Rüegg, Associate Professor at Karolinska Institutet, Sweden and Vice-Coordinator of EDC-MixRisk project. “We also identified common molecular targets of these mixtures, for example the thyroid hormone signaling pathway. As proper levels of thyroid hormone are essential for foetal development, interference can lead to increased susceptibility to diseases later in life,” she explains.
“We also tested selected single chemicals and compared their effects to the mixtures. In most cases, the single substances did not have an effect at concentrations comparable to the mixtures,” she adds. This points to the importance of assessing mixture effects which are often overlooked, although evidence from research is mounting.
Finally, novel approaches for a more systematic risk assessment are being developed in the project to find better models for addressing mixture effects on human health. One of the key findings by EDC-MixRisk researchers underscores that the regulatory guideline values for various single chemicals should be lower than the current ones because of the combination effects. The results suggest that the currently used chemical-by-chemical approaches underestimate risk by a factor that ranges from 1 to 100 for different chemicals. An article describing these findings was recently published in Environment International.
“We have to intensify our efforts in order to increase our understanding and most important of all, to take proper approaches and strategies that will reduce the harm and risks to human health and environment from these hazardous mixtures,” concludes Dr. Rüegg.
EDC-MixRisk has received funding from the European Union’s Horizon 2020 research and innovation programme. It has been highlighted as a success story among EU-funded research projects.
Watch a short video about the EDC-MixRisk Project here.
Vice-Coordinator of EDC-MixRisk, Associate Professor
Karolinska Institutet, Swetox & Institute for Environmental Medicine, Sweden
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Professor, Karlstad University, Sweden and
Icahn School of Medicine at Mount Sinai, New York City, USA
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Project and Communications Manager,
EDC-MixRisk Coordination Office
Karolinska Institutet, Swetox, Sweden
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