Endocrine disruptors are chemicals that interfere in one way or another with hormones in the body. There's absolutely no question that in low concentrations they can have damaging effects in animals. Since it's not possible to do comparable experiments that test toxins in humans, we're not certain about the effects in people.
DDT is an endocrine disruptor. Bisphenol-A is also an endocrine disruptor. Bisphenol-A is used as a building block in various polymers and polymer additives, including plastic bottles like those used to feed milk to babies.
Toxicologists, the Environmental Protection Agency, the Food and Drug Administration, and nearly everyone who pays attention to environmental chemical pollution, have known about bisphenol-A for many years. In the news today is the prospect that Canada is about to ban the use of bisphenol-A as an ingredient in plastic bottles, beverage containers, food containers, and linings in food cans.
Obviously, bisphenol-A is all over the place, and banning its use may cause some corporate heads to go apoplectic -- business disruption to end endocrine disruption.
It's a problem, but the scientific evidence for the dangers of low concentrations of endocrine disruptors is strong enough for scientists to be alarmed.
Today's news focuses on possible effects on babies and children and adults. More insidious are possible effects on the developing fetus. Here are some examples:
The male incidence of anorexia nervosa is only one-tenth that in females, but if you're the male part of an opposite sex twin pair, your probability for anorexia nervosa is about the same as your twin sister, close to the general female incidence. The suspected culprit: environmental endocrine disruptors impacting fetal development.
The animal evidence concerning endocrine disruptors is startling. Studies show that male fish in detergent-contaminated water express female characteristics, turtles are sex-reversed by PCBs, male frogs exposed to a common herbicide form multiple ovaries, pseudohermaphroditic offspring are produced by polar bears, and seals in contaminated water have an excess of uterine fibroids.
Transient exposure of a gestating female rat during the period of gonadal sex determination to the endocrine disruptors vinclozalin (an antiandrogenic compound) or methoxychlor (an estrogenic compound) induces decreased spermatogenic capacity (cell number and viability) and increased incidence of male infertility in nearly all males of all subsequent generations examined.
The impact of endocrine disruptors on fetal sexual development, gender identity, and sexual orientation is based on the influence of hormones in designing the sexuality of the embryo and fetus. Research shows that changes in sex hormone levels during prenatal sexual brain organization can be responsible for long-term changes in gonadotropin secretion, sexual orientation, and gender-role behavior.
One idea circulating among some scientists is the possibility that prenatal exposure to endocrine disruptors such as bisphenol-A can be involved in the etiology of schizophrenia.
Some people think the way to solve these problems of chemical pollution is to do cost-benefit analysis. I think that idea is stupid. A valid cost-benefit analysis in this context involves assigning a reasonable monetary value to human sickness, misery, or death. A reasonable monetary value? Do you think that's possible? As they say in my town, fuggedabowdit.
So what do we do? Maybe my grandmother had the right idea: Better safe than sorry. She was talking about waiting for the walk sign before you cross a street, but maybe her counsel should be applied in other places also.
Anyway, what it boils down to is a crapshoot. My gut feeling is that crap tables belong in Las Vegas and that kids born and unborn are not yet fit to play craps.