ABSTRACT
Male infertility Falling sperm counts There has been a significant literature in recent years concerning the possible effects of environmental pollutants (possibly estrogens) on the increasing rates of cryptorchidism and germ cell tumors and the decline in sperm concentrations over the last 20-50 years. Few of the studies were performed prospectively and most observed either sperm donors or men undergoing vasectomy. In many of the studies important factors such as age, ejaculatory frequency and periods of abstinence were not controlled for. Single samples from men are also misleading as there can be huge fluctuations in the same individual.
