Sperm quality
Scientists in charge of human reproduction are concerned over the last twenty years. The fertility of the human species has not diminished, but the quality of sperm has decreased in the last fifty years. The number of sperm is constantly decreasing, but French experts have added another element to the problem: the evolution and quality of sperm is different in each territory. In the samples collected in the center of Rennes 87 million sperm have been detected per millimeter of sperm and in the collected in the center of Tolosa only 72 million. Scientists have not explained why these differences.
On the other hand, according to a study published by Inserm, between 1974 and 1994 the number of sperm in the Paris area has decreased, but in Toulouse, for example, there has been no decrease. In the United States there are also territorial differences, but sperm concentration has increased considerably between 1970 and 1994.
Zu idazle
Zientzia aldizkaria
