Geographical differences in semen quality in a population of young healthy volunteers from the different regions of Spain

Numerous studies have shown geographical differences in semen quality even within a given country. We have previously reported a low semen quality in volunteers from the province of Barcelona compared with the general population. The objective of this study was to determine the semen quality in a population of young healthy volunteers from the different regions of Spain. A total of 1239 volunteers between 18 and 30 years of age were enrolled. The parameters evaluated were semen volume, sperm concentration and progressive sperm motility. The results indicate that while there were no differences in semen volume or sperm motility, there were statistically significant differences in the rate of oligospermia in volunteers from the different regions studied. The prevalence of oligospermia was highest in Valencia (22.7%), Barcelona (22.7%) and Pais Vasco (18.7%), which are the regions of Spain with the highest degree of industrialisation for the last 50 years, and lowest in Galicia (8.5%) and Andalucia (13.7%), regions with a more recent industrial development. There were no differences in the rate of oligospermia as a function of age. These results support the hypothesis that exposure to environmental toxicants may affect the process of spermatogenesis leading to meiotic alterations, maturational arrest and oligospermia.