THE ESSENTIAL
- Infertility corresponds to the absence of pregnancy despite unprotected sexual intercourse for a period of at least twelve months.
- Up to 25% of infertility cases are unexplained.
About one in eight couples consults a health professional for difficulties in conceiving a child in France, according to theInserm. In three quarters of cases, infertility is of either male or female origin, or it associates both sexes. To better understand male infertility, two researchers, Andreas Kortenkamp from Brunel University in London and Hanne Frederiksen from the University of Copenhagen, worked on the link between everyday pollutants and the decline in sperm quality. Their study has just been published in the scientific journal Environment International.
“Nine chemicals tested in urine samples”
According to scientists, the mixture of chemical pollutants in everyday products might explain the decline in male fertility. To reach this conclusion, the authors analyzed “nine jointly controlled chemicals in urine samples from 98 young Danish men”. Thus, the authors found several substances dangerous for the fertility of men. Bisphenols (A, F, S) first of all, which are present in the manufacture of electronic equipment, food packaging, but also in varnish or paint.
The list of hazardous pollutants
Phthalates (DEHP, DnBP, BBzP, DiNP) are also pollutants detected in humans. These substances are generally present in the packaging of household and food products. There were also polychlorinated dioxins, products present in food, and butylparaben, a component of certain cosmetics, in the urine samples of the young men. Finally, the last dangerous substance detected: paracetamol.
According to the authors, the median level of exposure to these substances is regarding twenty times higher than the current risk threshold. For some products, it was even 100 times higher than this threshold. For the authors, it is therefore this over-exposure to pollutants that would explain the decline in male fertility.
But other factors may also explain this phenomenon. According to Inserm, “abnormalities of spermatogenesis (formation of sperm) are by far the most common causes of male infertility. Abnormalities can relate to the quantity or quality of spermatozoa”. To this are added other elements, directly related to the hygiene of life, such as smoking, diet, stress or overweight.