A doomsday scenario of an end to human sperm production has been back in the news recently, now with the added threat of shrinking penises.
Professor Shanna Swan, a US epidemiologist who studies environmental influences on human development, recently published a new book called Countdown.
In it, she suggests sperm counts could reach zero by 2045, largely owing to the impact of a range of environmental pollutants used in manufacturing everyday products: phthalates and bisphosphenol A (BPA) from plastics, and per- and poly-fluoroalkyl substances (PFAS) used, for example, in waterproofing. Under this scenario, she says, most couples wanting to conceive would need to rely on assisted reproductive technologies.