There I stood, almost 14 years ago, at a San Francisco airport counter, waiting for the agent to hand me my ticket. The “Today” show had arranged to fly me to New York to tell the world about a story I’d written for an early issue of Mother Jones concerning the 40 percent decline in men’s sperm counts since the 1930s, and the possibility that low-level, everyday exposure to pollutants threatened human reproduction.
“Castleman…” the agent murmured, scanning his screen. “Here you are, first class to New York. No, wait. This is strange. Your ticket has just been canceled.”
Canceled? I telephoned “Today.” “Sorry,” the producer explained. “We decided not to go with your sperm story. It just isn’t solid enough.”
Fourteen years later, the sperm crisis still hasn’t cracked prime time. A few scattered, incomplete reports have appeared here and there over the years–recently in Newsweek and the New York Times–but the major media have not given this story the attention it deserves. Yet it is clear that the alarm Mother Jones sounded in 1982 should be ringing louder than ever. The story has become more disturbing than even the most paranoid environmentalist would have imagined. The sperm crisis turns out to be just one aspect of a bigger environmental crisis that links male fertility problems with the accelerating disappearance of wildlife and the increasing epidemic of breast cancer in women.
What could possibly account for such disparate problems? Xenoestrogens–chemicals that look nothing like the female sex hormone estrogen but have similar effects. Some of these estrogen mimics are chemicals environmentalists have opposed for years: PCBs, DDT, and other pesticides and industrial pollutants. But many other chemicals have taken the scientific community by surprise, such as nonylphenol, which is widely used in plastics and that even staunch environmentalists considered benign–at least until recently.
Xenoestrogens do their dirty work by breaking a classic tenet of biochemistry: the rule that chemicals that have similar effects have to have a similar molecular structure, because chemicals bind to cellular receptor sites in lock-and-key fashion. But despite a different structure, xenoestrogens are able to bind to estrogen receptors. They are, in effect, female sex hormones in disguise.
Sex hormones and their mimics are very potent. Even low-level exposure to xenoestrogens kills sperm. Similar low-level exposure also disrupts wildlife reproduction. Animal studies over the last decade show bizarre reproductive anomalies, including an epidemic of penile malformations among alligators in the Everglades. In the Great Lakes, fish populations have become hermaphroditic, with males developing female genitalia. Studies in England document similar gender-bending changes–all in waterways contaminated with xenoestrogens, some of which are not necessarily pollutants.
Finally, as I reported in “Breast Cancer Cover-Up” in Mother Jones (May/June 1994), xenoestrogens also appear to contribute to the breast cancer epidemic. Estrogen has long been known to stimulate the growth of breast tumors. It appears xenoestrogens do as well.
I suspect I was dumped from the “Today” show because some producer checked my original Mother Jones article with some researcher who spouted the scientific consensus of the time: There was no sperm crisis; allegations of one were a paranoid’s nightmare. Back then, scientists had plausible comebacks for every discovery that pointed to a decline in male fertility. Yes, many studies showed plummeting sperm counts, but several did not. Sure, a Florida State chemistry professor had discovered sperm-killing pollutants (PCBs and other toxic chemicals) in the semen of students with low sperm counts, but without corroboration, that lone study meant nothing. Yes, clusters of sterility had turned up in men working in pesticide plants, but the men’s sperm counts returned to normal after additional factory safeguards reduced their chemical exposure.
Sperm-crisis skeptics insisted that the alleged sperm decline was a meaningless fluke caused by changes in men’s underwear and sperm-counting techniques. The reference to the change in underwear pertained to the trend away from boxer shorts to jockey shorts. Jockey shorts hold the testicles unnaturally close to the body, warming sperm (which die by the thousands when heated). If underwear were not responsible, argued the skeptics, then changes in counting techniques surely were. Researchers in the 1930s had counted sperm manually; by the 1970s, counts had become computerized.
But since “Today” canceled my ticket, the sperm crisis has become undeniable. During the 1980s, a New York urologist tested the notion that tight-fitting underwear lowered sperm counts. His conclusion: Men who wear jockey shorts have the same sperm count as men who wear boxers.
Then, in 1992, Danish scientists confirmed that men’s average sperm count has declined 42 percent since 1940. The University of Copenhagen researchers analyzed 61 sperm-count studies from a 50-year period, the largest review ever, and excluded those that used computerized counts. Since the Danish report, two more studies have shown a decline in men’s sperm counts.
Meanwhile, the sperm-crisis story has taken an ominous turn. Until a few years ago, researchers knew of no link between the sperm crisis, wildlife feminization, and the breast cancer epidemic. Then, independently, various researchers began focusing on xenoestrogens, and the connection became clear. The world is rapidly becoming an estrogen bath, and as living things soak in it, they all fall victim to estrogenic effects.
The case against xenoestrogens is slowly going mainstream. Recently, the Journal of the American Medical Association published a comprehensive article that sounded a warning about the estrogen hazard. At the same time, a small but vocal group of scientists is calling for hormonal screening of all chemicals in wide use, with rapid phaseout of those shown to be most estrogenic. Unfortunately, given the mood in Washington, any phaseout seems unlikely.
The xenoestrogen peril is not yet front-page news, but it would come as no surprise to Rachel Carson, the early environmentalist who in 1962 first pointed an accusing finger at DDT. Today we recoil from DDT and other toxic chemicals because they are proven or suspected carcinogens. But 34 years ago, when Carson published her landmark book, Silent Spring, she focused not on cancer, but on the fact that DDT disrupted songbird reproduction, decimating their numbers (hence the title, Silent Spring). Apologists for the chemical industry dismissed her as a nut, just as they continue to insist that all’s well with human and animal reproduction. But today we know that DDT represents just the tip of a massive, worldwide xenoestrogenic iceberg, and that all the world’s animal species are on board a figurative Titanic heading right for it.
Michael Castleman is a contributing writer to Mother Jones. His most recent article, “To Hell With Harvard,” covering breast cancer research, appeared in the Nov./Dec. 1995 issue. His latest book, Nature’s Cures, is being published this month by Rodale Books.
