The classic example is diethylstilbestrol, or DES. The oestrogen-like drug was administered to millions of pregnant women between 1948 and 1971 to prevent spontaneous abortions. But it upset the delicate hormonal balance in the womb and ended up causing genital defects in many of the women's children, including vaginal deformities in girls and undescended testicles and abnormally small penises in boys. In the past decade, scientists have found that the number of environmental contaminants with oestrogen-like properties is much greater than they had imagined. The list includes: (a) DDE, a contaminant in dicolfol, an insecticide sprayed on food crops in the USA. (DDE is also the major breakdown product of DDT, an insecticide that is banned in some countries but still in wide use around the world); (b) Nonylphenols and related compounds found in spermaticides, hair colouring products and other toiletries plastic wrappings, furniture polish, herbicides and pesticides; (c) Polychlorinated biphenyls, a family of chlorine-containing industrial compounds, not longer made in certain countries but still in use. They have become widespread contaminants in food and water and are commonly found in human fat tissue and breast milk; (d) Endosulfan, a pesticide used on vegetables; (e) Bis-phenol-A, a breakdown product of polycarbonate plastics from which many plastic water jugs and baby bottles are made.
The most staggering feature of the problem is its scale. The accused chemicals are found in pesticides, refrigerators, medicines and cans of beans. They have been found in Antarctic snow and in the air almost 7,000 metres above India. Recent findings and circumstantial evidence that points to pollution by hormonally active chemicals are that sperm counts in men have fallen drastically worldwide during the past five decades, while the number of testicular cancers has tripled. There is an epidemic of endometriosis among women. Alligator eggs are failing to hatch at a biological research institute in Florida, and many male alligators have abnormally small phalluses. Cancer researchers are finding that routine cell culture experiments have suddenly stopped working because oestrogenic chemicals were leaching out of laboratory plastic tubing.
2. In a 1997 study, male mice developed abnormal prostate glands after receiving a very small extra dose of a chemical called oestradiol while they were still in the womb.
3. The problem is enormous, but there is little we can do, because the offending chemicals are so prevalent and society is unwilling to sacrifice its modern comforts.
4. Soya products are a particularly good source of oestrogens and their consumption has increased considerably since the 1970s.