Secular variations in sperm quality: fact or science fiction?

Abstract

The debate concerning the possible degradation in human sperm quality began in the 1970s, was revived at the beginning of the 1990s and has continued to mobilize the scientific community ever since. After the meta-analysis by Carlsen et al. (1992) showing a decline in human semen quality over the last 50 years, several groups investigated the sperm characteristics of more or less homogeneous groups of men who had provided semen at the same center for 10 to 20 years. A significant decrease in sperm concentration was reported in some studies, but not in others. Meanwhile, there is an increasing number of reports suggesting that physical and chemical factors introduced and spread by human activity in the environment may have contributed to sperm decline. At the end of the 20th century the debate on declining semen quality is not closed. The lack of certainty and the serious consequences that such a decline would have on the fertility of human populations make this an important public health issue at the start of the 21st century. For this reason, intensive research should be developed in both fundamental and epidemiological domains, particularly in South America, where industrial and agricultural pollution pose a serious threat to the population.

Recombinant human estrogen, androgen and progesterone receptors for detection of potential endocrine disruptors

“…By using only the "binding assay", it is not possible to determine whether the binding is preliminary to an agonistic or to an antagonistic effect of an interacting chemical. Nevertheless, the interactions with hPR described here probably contribute to the hormonal disorders described in humans [4,5,6,7,8,9,10,11,12].…”

“…In humans, endometriosis [5] and testicular cancer [6] have been linked to exposure to organochlorine and plasticizers, respectively. A general decline of the male reproductive health is observed and imputed to EDC [7,8,9,10,11,12].…”

Simultaneous Determination of Ten Endocrine Hormone Disrupters in Water Using SPE/LC-(ESI)MS-MS

“…Potential adverse outcomes in humans are mostly described as effects on reproductive and sexual development and function [8,9], such as decreased sperm quality and increase in subfertility [10][11][12][13][14], changes in sex ratio [15,16], puberty disorders and higher incidence of cryptorchidism and hypospadias [9,12,15,[17][18][19].…”

A produção do conhecimento da saúde pública sobre a relação homem-saúde: uma revisão bibliográfica

“…No conjunto das fontes estudadas, ressaltam-se as seguintes conclusões sobre os comprometimentos da reprodução masculina: (a) há estudos internacionais do final do século XX que relatam a diminuição significativa na concentração de espermatozóides, e esse declínio pode estar associado à poluição industrial e agrícola e pode aumentar o número de casais infecundos 40 ; (b) estudos publicados em 1938 e 1990 sugerem um declínio na concentração de esperma e no volume do sêmen 41 ; (c) há uma preocupação crescente no sentido de que as exposições ambientais a diversos produtos químicos atuem contra a reprodução masculina 39,42 .…”