A European study published in Science shows the impact on the development of intellectual disability of prenatal exposure to mixtures of endocrine disruptors, chemicals that enter the human body through water, food and air

A European study just published in Science reveals that you determine mixtures of chemicals to which we are continuously exposed can interfere with the endocrine system (of mother and fetus) during pregnancy and increase the risk of neurological deficit in the unborn childin particular with regard to language delays.

The study, called EDC-MixRisk, was conducted between Swedish, Italian, French, Finnish, German, Greek, British and American universities and research centers. For Italy, scientists from the University of Milan, the European Institute of Oncology and Human Technopole worked there.

The research was carried out in three phases: monitoring of about 2,300 pregnant women, registered in the Swedish study called SELMA; experimental tests carried out in the laboratory (also in Italy) on in vitro models and a posteriori epidemiological comparison.

In first stage were measured concentrations of bisphenols, phthalates and PFAS present in the blood and urine of women monitored at the 10th week of pregnancy. These substances are part of the so-called endocrine disruptorschemical compounds that have already been shown to be capable of alter hormonal functions, with repercussions on health. The children born to the mothers involved in the study were followed up to 30 months of life: their cognitive abilities were measured (through the number of words spoken) and the chemical mixtures to which the mothers had been exposed during gestation were identified and which resulted associated with a delay in language development.

There second phase took place in the laboratory, chemically synthesizing the same combinations to reproduce the doses found in women: We put these mixtures in contact with cerebral organoids – explains al Courier service
Giuseppe TestaPrincipal Investigator of EDC-MixRisk of human experimental modeling, professor of molecular biology at the University of Milan, group leader at the European Institute of Oncology, in whose laboratories the study took place, and director of the Human Neurogenomics Center Technopole, where this line of research will continue -: they are very sophisticated cellular models in vitro that reproduce fundamental aspects of the development of the human brain and do so in a dynamic way, that is, with similar timing to those with which the brain develops in vivo. When neurons came into contact with these substances, alterations were produced in a whole series of hormonal adjustments that affect the genes responsible for intellectual disability and autism.

Once established, based on the data collected, new risk thresholds of the blends in question, the third stage of the study calculated how up to 54% of pregnant women Swedes had been exposed at the thresholds considered on guard: Obviously this did not translate into the fact that 54% of children had a delay in language development – explains Testa -: exposure to the mix of substances a contributing causethen a genetic predisposition of resistance or vulnerability to the damage induced by these mixtures comes into play.

For the first time, however, the researchers conducted the same experiments also with the single substances and have seen that the mixture acts differently. For this they appeal to the authorities to whom the regulation is delegated: What we propose, on the basis of these data – says Testa – that the approach should be changed: up to now the threshold limits of each substance have been established individually, time to regulate also for blends. Even if each of these substances taken alone below the risk threshold, in fact, the fact of being exposed every day to dozens, hundreds of endocrine disruptors represents a much greater risk.

The combination studied in this case by the researchers consists of very common substances, which are found in plastic derivatives, in beverage containersin building roofing materials, building paints and more: definitely a type of so pervasive and continuous exposure in such time as to make it impossible for individuals to choose not to expose themselves – observes Testa -. Precisely for this reason, the management of regulation cannot fall on the shoulders of consumers (who can also make their voices heard), but must be evaluated in the context of the authorization processes for the production and marketing of a wide range of products, starting with plastic derivatives, up to cosmetics and pesticides.
With the study just published, the scientific foundations have been laid for a radical revision of national and international risk assessment policies, up to now based on the examination of single substances and not of their mixtures.