Pollution and lifestyles are at the origin of an accelerated fall in the concentration of sperm in humans. This decline is now observed worldwide, indicates a meta-analysis published Tuesday, November 15.
by Stéphane Foucart
The rapid decline of male fertility does not only concern northern countries, but the whole world. Far from slowing down to stabilize, the phenomenon is in strong acceleration. These are the protruding elements of synthetic work, published Tuesday November 15 in the journal Human Reproduction Update , the most exhaustive led to date on the fall in the concentration of sperm in humans.
The causes of this decline have been, for the past twenty years, the subject of numerous research, pointing to individual factors linked to lifestyle (smoking, sedentary lifestyle, food, etc.) and environmental causes related to the air pollution, various drugs and the omnipresence of certain summary substances in the environment and the food chain (plasticizers and pesticides in particular).
Hagai Levine epidemiologists (Hebrew University of Jerusalem), Shanna Swan (Faculty of Medicine Mount Sinai in New York), and their colleagues brought together the results of all published studies – several hundred – on the subject. They identified data available in more than fifty countries, covering the period 1973-2018.
According to their results, during these forty-five years, the average concentration of gametes in the sperm of the general male population increased from 101 million per milliliter (m/ml) to 49 m/ml. A level already considered that of a “subferlet” man, underlines Dr swan. “France is no exception, specifies Hagai Levine. In France, thanks to the availability of good quality data, we are certain that there is a strong and lasting decline, as elsewhere in the world.”
a threat “for the survival of humanity”
Including all data after 1973, the average rate of the fall is 1.16 % per year worldwide. This pace has more than doubled since the beginning of the XXI e century, going to a decline of 2.64 % per year over the period 2000-2018. An acceleration qualified as “alarming” by the authors. “Our results are like the Canari in the mine,” says Levine. We have a serious problem in our hands which, if it is not controlled, could threaten the survival of humanity. “Nothing less.
“In this meta-analysis, the most important ever made on the quality of the sperm, Hagai Levine and his colleagues show a continuous drop in the number of sperm, confirms the toxicologist Andreas Kortenkamp (Brunel University, in London), who n ‘did not participate in this study. The strength of this work is to show for the first time that these trends also concern the countries of Africa and South America. It is really worrying. “
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