Published in journal Environmental Health Perspectives, this work emphasized that exposure of pregnant women to certain phenols and phthalates is associated with behavioral disorders of boys 3 to 5 years of age. Of se, three chemicals are of concern: bisphenol A, triclosan and dibutyl phthalate (DBP).
Bisphenol A, which was banned in all food containers in 2015 - a date later than this study - is still used in a multitude of common objects (CDs, bicycle helmets, etc.). Triclosan, for its part, is an antibacterial agent found in soaps, toothpastes or shower gels. Its use has been prohibited in clothing and restricted in certain cosmetics such as shaving foams. Finally, DBP is used as a plasticizer in plastics of PVC type, certain glues, nail varnishes or hair lacquers."Strengths and Difficulties Questionnaire"
The study involved 529 boys from mor-in-law cohort Eden, set up by Inserm. The mors of se boys were recruited when y were pregnant, between 2003 and 2006, in Nancy and Poitiers university hospitals.
Urine samples were collected in middle of second trimester of pregnancy. Then mors were asked to complete a questionnaire at 3rd and 5th birthdays of ir children. This "Strength and Difficulty Questionnaire" provides a score in several dimensions of child's behavior: emotional symptoms, peer relationship problems, driving problems, hyperactivity, inattention problems.
"Between 70% and 100% of se women were exposed to detectable levels of different substances," Inserm said. "Triclosan was detected in 80% of women, bisphenol A in 100%," says epidemiologist Rémy Slama, whose team of environmental epidemiology of Institute for Advancement of Biosciences (Inserm / CNRS / Université Grenoble Alpes) led study, carried out by Claire Philippat, with American Centers for Disease Control and Prevention.
By comparing questionnaires and exposure of mors to se chemicals during pregnancy, results are clear: for first time, study shows an association between exposure to triclosan and an increase in frequency of disorders emotional and relational relationships among boys.Relational disturbances
The team of Rémy Slama had already shown in 2014 effect of triclosan on cranial perimeter at birth, in this same cohort. "At molecular level, triclosan is able to interact with thyroid axis, which during pregnancy is involved in development of brain of fetus," Inserm points out.
Anor problem is that DBP is correlated with more emotional and relational disorders, including withdrawal behaviors at age 3, but not at age 5 for emotional disorders. Similarly, exposure of pregnant women to bisphenol A East associated with an increase in relational disorders at 3 years and more hyperactivity at 5 years.
All of se chemicals were found in urine at low levels that did not exceed regulatory thresholds. Yet "chemicals, even at very low doses, can disrupt hormonal functioning, sensitive to extremely small variations," notes Rémy Slama, who believes that triclosan should be banned.
Especially since presence of endocrine disruptors in food or cosmetics is not subject to compulsory labeling, so that we are now exposed to se products invisibly, limiting possibility for pregnant woman to protect herself."Cognitive Problems"
For Robert Barouki, who heads a unit of toxicology at Inserm, "this study supports idea that exposure during pregnancy to endocrine disrupters may be associated in some cases with cognitive and behavioral problems that appear later in child ". One of limitations pointed out by Rémy Slama is that pregnant women have only carried out a urinary collection, which may lead to an underestimation of effect of pollutants on health, as researchers have shown.
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Scientists have also not been able to study effects of endocrine disrupters during pregnancy on autism spectrum disorders, which would have involved tracking tens of thousands of children, Inserm notes. In any case, this study will support ongoing reflections on regulation of endocrine disruptors. A decision of European Commission is expected imminently.