Will future generations be less intelligent? If exposure to endocrine disrupters is maintained or even continues to increase, this may well be case. Many substances appear to be threatening developing brains. In question, ability of certain molecules to interfere with thyroid system, indispensable for harmonious development of brain in embryo.

There may be or mechanisms that still need to be identified. We now have solid toxicological data demonstrating that some substances interfere with thyroid axis and cause cognitive impairment and behaviour in animals. In humans, cohort studies tend to confirm this effect for some substances with increased risk of loss of QI, autism or hyperactivity, ' explains Rémy Slama, an epidemiologist at Inserm.

Results that challenge

The substances in issue are PCBs, which are now banned but very persistent in environment, some polybrominated compounds, pbdes (flame retardants), organophosphate (pesticides), bisphenol A or some phthalates. However, pregnant women and young children are constantly exposed to se substances, which are ubiquitous in environment. Only exposure to bisphenol A may have decreased since it was banned in food containers in France.

To try to see more clearly, researchers are following population groups to assess linkages between exposure levels and se risks, as with "" "" ("endocrine disruptors") Cohort: Longitudinal Study of (Pregnancy, infertility and childhood). Cécile Chaturvedi, also an epidemiologist at Inserm, and or researchers thus follow, since 2002, 3 500 women initially pregnant and children from se pregnancies.

Risk losing IQ points?

"We found a link between in utero exposure to organic solvents and increased risk of hyperactivity, even aggressiveness, at age 2, or risk of QI loss at 6 years." We also see a link between exposure to PBDEs during childhood and loss of IQ at age 6. The results are not alarming but affect impact of certain substances. The decrease in performance is about 5% when comparing one-third of children most exposed to PBDEs to or third of least exposed children. It is as if child was tired and less efficient, she illustrates. Conversely, we did not find any association with organophosphate insecticides while previous work suggested a link. Perhaps because our participants have a fairly high level of education and intellectual stimulation would compensate for a possible loss of se few IQ points in ir children?

The latter point clearly proves complexity of deciding on actual effect of substances. "There are a lot of factors that can distort interpretations when it comes to environment," says Dr. Robert Balakundi, toxicologist at Inserm-Université Paris Descartes. Not to mention that se pollutants are often evaluated independently of each or while individuals are exposed to a cocktail of molecules that can interact with each or and modify ir respective functions. "The level of evidence is not yet well established," confirms Prof. Gérard Amena, Deputy Director general of Scientific Affairs at Anses.

A drop in overall creativity

This did not prevent a group of researchers from trying out a small exercise based on data currently available. They calculated cost to society of se potential losses of IQ and increase in cases of autism and hyperactivity. They come to sum of EUR 150 billion per year for Europe, including a drop in overall creativity or care and social support of children in question.

Date Of Update: 07 October 2017, 12:10