A new paper published in the scientific journal Science illustrates the widespread exposure of people to a whole range of problematic chemicals. The paper, Neurotoxic mixture effects of chemicals extracted from blood of pregnant women, demonstrates the potential for individual chemicals to be more harmful when acting together.
Researchers from the Helmholtz-Centre of Environmental Research – UFZ, Germany analysed blood samples taken from 624 pregnant women for a range of chemicals.
They identified 294 substances from different chemical classes in the samples, including substances used in consumer goods, personal care products, food, and pesticides. Though the number of chemicals found in each sample varied, all of the pregnant mothers carried a complex cocktail of chemicals. This diversity and complexity in chemical exposure is representative for adults in general.
Subsequently, the scientists used a cell-based bio-assay to evaluate the neurotoxic mixture potential. They used designed mixtures in concentration ratios as they were found in the samples to assess how chemicals in realistic and complex mixtures act together. Crucially, they confirmed additive and detectable mixture effects at concentrations that were below the individual chemicals’ effect thresholds.
Concerns about potential impacts on the nervous system and brain development
The potential of chemicals to cause neurotoxic effects is of particular concern due to the implications for the development of the nervous system and the brain development of children. CHEM Trust highlighted this some years ago in our report No Brainer: The impact of chemicals on children’s brain development: a cause concern and a need for action.
CHEM Trust calls for policy action on mixture effects
Ninja Reineke, Head of Science at CHEM Trust, said:
“This combined chemical and effect-based analysis is very significant. It adds to the growing body of evidence illustrating that chemicals contribute to mixture effects even if the individual chemicals are below their effect doses. We have seen this many times in environmental samples and this paper demonstrates the relevance in highly complex human samples. Regulators must consider overall exposure to protect health and wildlife.”
CHEM Trust has long advocated for combined effects to be better addressed in regulatory decisions, and in 2022, published the report Chemical Cocktails: The neglected threat of toxic mixtures and how to fix it. In the report, we call for urgent action from the EU to better protect people and the wider environment from exposure to real-life chemical cocktails. In our analysis, there are workable and effective policy solutions available to address this complex problem, such as the use of a mixture assessment/allocation factor (MAF).
Read more in the press release from Helmholtz research center in English and German.
