Burger, Alyssa, E Magazine
More than 40 Common Chemicals Are 'Endocrine Disruptors' - Attacking the Body's Centers of Sexuality, Growth and Development
Since the early 1960s, scientists have observed some shocking mutations in wildlife - hermaphroditic seagulls with both male and female sex organs, eagles with crossed beaks, panthers born with undescended testicles, alligators with shriveled penises (see Currents, January/February 1996), and fish gonads which aren't distinctly male or female. In many of the affected populations, the animals have higher rates of reproductive failure and their numbers are in serious decline. But do any of these developments-brought on by our increasingly contaminated environment - have implications for the human population? Scientists say that evidence is mounting.
When experts from the fields of anthropology, comparative endocrinology, immunology, medicine, reproductive physiology, toxicology and wildlife management met at the Wingspread Conference in Racine, Wisconsin in July 1991, they agreed that both humans and wildlife are facing an increased risk of disease and deformity from common industrial and commercial chemicals.
Since listing began in the 1960s, more than 40 chemicals have been identified as "endocrine disruptors," interfering with sex, growth and development centers of the pituitary, thyroid, adrenals, ovaries and testes. These chemicals have also been shown to play tricks on the endocrine system by acting like a natural hormone or by blocking normal hormone functions.
But, endocrine disruptors also do not seem to be damaging our ability to reproduce. According to The National Center for Health Statistics, infertility for women between 15 and 44 has actually decreased since 1976.
A Dormant Menace?
So why be concerned? Fertility, unfortunately, is not the only indicator of endocrine disruptors at work. Scientists have related other disturbing trends to the work of these chemicals:
* In the last three decades, the rate of testicular cancer has tripled;
* There has been a 400 percent increase in ectopic pregnancies (formed in the fallopian tubes) in the U.S. between 1970 and 1987;
* Great Britain has reported a doubling of cryptorchidism (undescended testicles) and a doubling of the prevalence of hypospadias (abnormal urethral opening) between 1970 and 1987;
* Several studies have suggested a 50 percent decrease in sperm count worldwide over the last 50 years. Scientists agree that even if a man's sperm volume is a third lower than the past generation, he would still remain fertile. But a gradual decline in volume and quality of sperm could push some men into infertility.
Scientists agree that endocrine disruptors are very persistent in the environment. According to Linda Birnbaum, director of Experimental Toxicology at the Environmental Protection Agency's (EPA) National Health and Environmental Effects Research Laboratory, dioxins have an average half-life of seven years. Some types of PCBs can persist in human tissue and blood from one to even 20 years.
A demonstration of the dangerous power of endocrine disruptors occurred in 1979 in Taiwan, when women who consumed rice oil contaminated with the industrial compounds known as polychlorinated biphenyls (PCBs) had children with numerous genetic and developmental problems and sons with abnormally small penises. …