Regional differences and temporal trends in male reproductive health disorders: Semen quality may be a sensitive marker of environmental exposures

► A decline in semen quality has been observed in many countries. ► Incidences of hypospadias, cryptorchidism and testicular cancer are rising. ► The four diseases are interrelated and can be caused by testicular dysgenesis. ► Endocrine disrupters ubiquitous in our environment probably contribute to the trends. ► The cocktail effect of various toxicants may be important for the adverse effects.