Where can I read about "dropping male fertility" as a medical thing? Just taking a blind guess, as someone who doesn't follow the medical field, I would suggest that increases in "infertility" are much more likely to be caused by the older age at which people are becoming interested in "fertilization" than environmental factors causing biological malfunctions. In other words, it's not that reproductive systems are breaking faster, it's just that people aren't using them until they're worse for wear.