Male Reproductive Status and Its Relationship With Man-Made, Hormone-Disrupting Substances: Studies in Flanders, Belgium

Sperm quality seems to have declined over time in certain regions in the world. This regional trend coincides with the progressive increase in the incidence of male genital tract anomalies including testicular maldescent, hypospadias and testicular cancer. The association of these pathologies has been called the ‘testicular dysgenesis syndrome’ (TDS). The possible implications of decreased male fertility cannot be underestimated. Couples attending fertility clinics have a higher chance of multiple pregnancies, preterm delivery and consequently also of low birth weight, which is a known risk factor for a number of pathological conditions at adulthood. Many studies suggest TDS to be caused by man-made endocrine disrupters, mostly chemicals initiating estrogen actions (xenoestrogens) or inhibiting the effects of endogenous androgens (anti-androgens). Thousands of man-made chemicals have been released into the environment in vast quantities since the chemical industry began to boom in the 1950’s. Humans and wildlife are exposed to these chemicals through their nutrition, the air, the water and, more importantly, through the placenta during foetal development. In order to reliably estimate the reproductive health risks posed by these chemicals, scientific programmes should pursue the identification of the routes via which humans and wildlife are exposed to these xenobiotics using biomarkers of internal and external exposure. These are new and important tools, complementary to the traditional chemical analytical techniques as they reflect the integrated response of an individual or test organism to multiple compounds, accounting for possible additive, antagonistic or synergistic effects.