A recent study found that the average human sperm count has decreased by 40 per cent over the past 50 years. As public anxiety grows about infertility, environmentalists are blaming man-made chemical pollutants. Faith Brooke takes a look at the confusing scientific evidence behind their claimby Faith Brooke / March 20, 1996 / Leave a comment
Are our gonads shrivelling? Is our sperm count falling, and are our sexual organs prone to cancers, malformations and misfunctions of a kind our fathers did not suffer? Are the man-made chemicals which are part of modern life to blame for these reproductive woes?
A nightmarish vision of a future Britain, whose middle-aged people have stopped bearing children and who are growing old in the bleak knowledge that their species will die out with them, is the backdrop for PD James’s novel The Children of Men. But her fears are not just the product of one writer’s imagination.
The subject has been the focus of a great deal of recent scientific study. In a report published last summer, the Medical Research Council’s Institute for Environment and Health (IEH) concluded that the reproductive health of both animals and humans has indeed worsened over the last 50 years.
There is evidence that humans are more likely than their parents to contract breast or testicular cancers, and that men are more likely to suffer malformations of the reproductive organs which range from hypospadias-an anomaly in which the urethra opens on the underside of the penis-or cryptorchidism (undescended testes). Testicular cancer is now the commonest cancer among young men in Scotland. In the US, reproductive disorders have made it to the top 10 work-related illnesses listed by the National Institute for Occupational Safety and Health.
Evidence is also emerging that both the amount and the health of sperm produced by many groups of human males around the world is falling. A 1992 study published by the British Medical Journal showed that the average sperm count of men in several different countries had decreased by over 40 per cent between 1940 and 1990. The research was criticised for selection bias, but other studies back up the result. In a study of sperm donors in Paris, the first ejaculates of 1,351 men donated at a sperm bank were examined over the period from 1977 to 1993. The concentration of sperm declined on average 2.6 per cent per year.
Things are even worse in the animal kingdom. Hermaphrodite roach swim the River Lea in Britain. Male alligators in Florida’s Lake Apopka have developed abnormally small sexual organs; their testosterone levels are only a quarter of the level of similar alligators nearby; they produce only half the usual number of viable eggs, and nearly half their young…