This topic is one I have found it rather difficult to write a post about. I've been sitting on this book review of John's for nearly eight months, but it is referenced in the next The Long View blog post, so I need to get it posted.
Perhaps what makes this so hard to write about is that it doesn't fit really well into the standard categories of early twenty-first century American politics. On the left, concern about endocrine disruption is subsumed into the larger environmental narrative, just one more chemical pollutant. Sometimes perhaps, the subject is even sublimated, such that you wouldn't actually know that it is sex hormones, estrogen primarily, that we are talking about. Or where they come from: hormonal birth control. Things like BPA are a distraction. Who cares about compounds that mimic estrogen when we are putting [relatively] massive amounts of actual estrogen into the environment?
On the right, this topic tends towards the increasing feminization of the Western world. On Twitter, #TooMuchSoy is a good example of the genre. Declining sperm counts are often cited as well, although I am a bit suspicious of the data here. Again, why the fascination with a pseudoestrogen like soy? A serious look at sex hormones in the environment looks at 17β-estradiol, not soy.
Maybe my problem with this subject is it looks so much like a political Rorschach test, everyone just reads their own ideas into it. I am pretty sure that messing with sex hormones is a bad idea, but I don't have any firm opinions on what the line should be here.
While John wasn't a scientist [nor am I], he did have a pretty good grasp on the politics of the Western world and its general intellectual trends. The conclusion to this review points out that the logical end of the rather plausible concerns about environmental contaminants is the complete destruction of the mid-twentieth century liberalism that spawned those concerns. If you add in the recent direction of genetics, this trend is even more pronounced. Fortunately, we humans have an amazing capacity to avoid the logical implications of our ideas, which I maintain is a feature not a bug.
Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival?
by Theo Colborn, Dianne Dumanoski, and John Peterson Myers
(With a Foreword by Vice President Al Gore)
$24.95, 306 pp.
One Apocalypse Too Many?
The authors and publishers of this book suggest more than once that it will be the "Silent Spring" of the 1990s. Vice President Albert Gore also says as much in his Foreword. This is no small claim. "Silent Spring," published in 1965, was the book that is often credited with starting the environmental movement. It warned of the dangers posed by manmade chemicals to wildlife. While this book is based largely on wildlife studies, its chief concern is the danger posed by manmade chemicals to man. There are two extreme ways to look at its thesis. This is the first way:
The Human Race Will Begin to Die Out in The Next Century!!!
To be fair, the authors (Colborn and Myers are zoologists, Dumanoski a science writer) say that they don't think it will come to extinction. However, if what they propose in this book is correct, we could be looking at a near future in which human populations collapse, while such children who are born will often be deformed or mentally unbalanced.
There is evidence. Recent studies from Denmark, France and Scotland found quite dramatic drops in human sperm counts over the past few decades. The declines are directly correlated with when the men in question were born. The Scottish study, published just this February, found sperm counts 24% lower in men born after 1970 compared to men born a dozen years earlier. The Danish study, published in 1992, found a decline of 50% over the last half-century, and it found it worldwide. No one claims to have detected an actual drop in human fertility because of these alleged changes. However, if the trends continue, widespread male infertility could occur by the middle of the next century.
Readers of P.D. James's novel, "The Children of Men" (1992), may find their skin crawling as they read this, since that book sets out a scenario reminiscent of the one suggested by "Our Stolen Future." The James book, of course, does not purport to be science. The cause of the fictional worldwide epidemic of sterility remains unexplained. The story is an allegory of the Last Days, in which a contraceptive-minded world gets more birth control than it bargained for. Perhaps James, most intelligent of mystery writers, had been aware of the research reported in "Our Stolen Future" and dramatized its possible implications in her book. At least, I hope that is the explanation.
"Our Stolen Future" does purport to be science. The culprits to which the authors point are hormonally-active, highly persistent chemicals. Most of them are artificial and have been released into the environment since the 1930s. These substances tend to have long names that are shortened to acronyms, such as DDT, PCB, DDE and DES. Some, like dioxin, are at least pronounceable, while others, such as lindane and the furans, are positively mellifluous. Few of these chemicals are poisonous in the conventional sense of the word. Most of them do not seem to be carcinogenic, at least in adult organisms. They have served as insulators and fire-retardants precisely because they are relatively inert. Others, just as chemically stable, were marketed for their useful biological properties.
The problem was that some of these chemicals turned out to have rather more biological properties than had at first been supposed.. The insecticide DDT has been banned in most developed countries because of its more subtle effects, particularly those that have shown up in wildlife. (Among other things, it weakens eggshells, an effect that almost extinguished the bald eagle, as well as a number of other egg-laying creatures.) DES was regularly prescribed for many years to prevent miscarriages. This was because the body reacted to the chemical as if it were the natural hormone, estrogen. Later, it was discovered that the daughters of women who had taken DES were prone to certain cancers and deformations of the reproductive system.
The problem with this whole group of chemicals is that, although they do not resemble anything in the natural world, some accident of structural chemistry permits them to act like hormones, or hormone inhibitors. They can thus affect the body's endocrine system, which regulates the growth, metabolism and reproduction of animals. Nature has been very conservative in this branch of biology: the estrogen found in turtles, for instance, is pretty much the same as that found in human beings. Thus, if abnormalities develop in animals because of these substances, the odds are very good they will also show up in people.
The authors provide a great deal of evidence that abnormalities are showing up in animals. The book presents us an appalling spectacle of hermaphroditic alligators, droves of dolphins with defective immune systems and sea gulls whose general sexual development is not all it might be. It is not hard to show in the laboratory that the chemicals in question can feminize males and masculinize females, often in response to concentrations of parts per billion or even trillion. Small exposures like this have no effect on adult organisms, and the authors are at pains to emphasize that no genetic damage is done. However, the effects of infinitesimal quantities of these chemicals on embryonic development can be dramatic.
When these abnormalities occur in the wild, it is often in connection with a history of local pollution, such as in Lake Erie. (Wildlife is coming back there, but some of it is a tad odd.) However, the most alarming thing about these substances is their ability to move up the food chain and across great distances. Since these chemicals are persistent, they are concentrated each time one creature eats another, so that the food chain acts as a natural distillery. Parts per trillion in algae, say, thus eventually become far more alarming parts per million in polar bears (and, for that matter, in the mother's milk of Eskimos). Thus, for instance, an echo of the deadly effects of DDT that appeared in Great Lakes birds in the 1970s are now appearing in the birds of the mid-Pacific.
The authors show, particularly with mammalian studies, how exposure to these substances can affect not just embryonic development but behavior in life. We are treated to quite alarming accounts of very aggressive female mice and of males that exhibit "playboy" behavior, such as the abuse and neglect of the young. They coyly mention some studies suggesting a correlation between these exposures and an increase in homosexual behavior in animals. More seriously, they cite studies that show a decline in the ability to solve problems in some creatures that had experienced prenatal exposure.
The authors characterize their own work as a "detective story." Though the book does not quite come up to the level of Agatha Christie (or P.D. James), nevertheless you will rarely find a more readable account of comparative endocrinology. The problem is that this is a detective story in which the murderer is not positively identified. In fact, it is never made altogether certain that there has been a crime. This brings us to the second extreme way in which this book might be viewed:
This Book Is the Last Gasp of Environmental Hysteria.
The environmental movement has been in a growing theoretical crisis for the last decade. The assumption on which most environmental activism is based, that ecologies can be "preserved" like rocks in a geology museum, has proven to be simply false. Animal populations and even forest cover fluctuate as chaotically as the weather, no matter what people do. Specifically regarding human health, it is now pretty clear the hysteria about "cancer causing substances" which began in the 1960s has little experimental support. Cigarette smoke and excessive sunlight really can cause cancer. However, almost all the other things we have been told to be afraid of during the last two decades cause cancer only in lab mice unfortunate enough to be fed several times their body weight of them. Some environmental concerns, notably the Greenhouse Effect, probably do have a basis in fact. However, the Greenhouse Effect is not ecology, it is physics. Ecology, in fact, is in danger of being reclassified to the "snake oil" section of the intellectual market, perhaps to sit on the same shelf as Freudian psychology and literary deconstruction.
"Our Stolen Future" is the perfect last redoubt of a "science" no longer on speaking terms with the facts. It is a universal causal model that cannot be disconfirmed by experiment. The universality of the problem is assumed. Early in the book, we are given accounts of working scientists puzzling over boxes of wildlife studies from all over the world. Some studies describe gulls with clubbed bills, some inexplicable die-offs of marine mammals, some a vast and inexplicable dearth of tadpoles. What could be causing all these strange events, the scientists wonder? Actually, it is not at all clear that any one thing is causing them, or even that they are unusual. The studies behind this book started to collect in the 1970s, when money and attention began to be directed to ecological research. Sure enough, anomalies began to be reported almost immediately. That does not prove the anomalies were new, however. It only shows that people had begun to look for them.
The problem with blaming everything on disruptions of the endocrine system is that it becomes impossible to blame anything in particular on such disruptions. Tiny changes in the amount of estrogen in the wombs of pregnant mice, we learn, can make the off-spring very aggressive. Or very passive. Or good parents. Or bad parents. In fact, we are given to suspect that the least tinkering with the endocrine system can cause just about any psychological effect in animals you can thing of, as well as a gamut of physical effects. The studies in question can only very rarely pin a specific effect to a specific chemical at a specific concentration. Further complicating the picture is a study showing that estrogen-like chemicals can work in tandem, so that even if no particular chemical is present at a dangerous level, the collection of them might still disrupt embryonic development. Well, I suppose it might. It is certainly impossible to prove otherwise.
There is no evidence, none at all, that the alarming reports about declines in human male sperm counts are due to the subtle effects of estrogen-like chemicals in the environment. (For that matter, it is not at all clear that the studies are describing a real phenomenon, since they use historical data collected from unrepresentative populations.) The closest the book comes to demonstrating any human health effects from these substances is a single study reporting excessive irritability in the infants of women who ate Great Lakes fish while pregnant. Descriptions of these hypothetical effects on human populations (or for that matter, animal populations) are scattered among results from studies saying what we already knew. Sure residual DDT can have a devastating effect on bird populations, and alligators who live in lakes where there have been chemical spills may turn out to be very strange alligators indeed. Still, one comes away from "Our Stolen Future" with the suspicion that not all the fishy things in the book come from Lake Erie.
"Our Stolen Future" could turn out to be as important as "Silent Spring," but not, I think, for the same reasons. This is not a particularly political book, though its recommendations do have a certain breadth, ranging from washing your hands frequently to essentially closing down the synthetic chemicals industry. However, it does quite innocently address most of the things that ordinary, sensible liberal people tend to be interested in. The results could be explosive.
Having sought to set out a theory that explains the whole known world in terms of environmental effects on endocrinology, the authors have accidently dissolved the liberal world, which is the world they know about, in a broth of PCBs and dioxin. Liberals are interested in "social questions," such as education, the role of women, the causes of crime, population control. The authors make suggestions about the causes of recent trends in all these areas. What they suggest is that the distinctive features of the world of the past thirty years have their origin in chemically induced pathology.
Of course you cannot prove that the decline in standardized test scores that began in the 1960s is due to DDT exposure in the womb. But then, there are those troubling studies about the decline in the intelligence of rats exposed in utero. Of course feminism has deep social and historical roots. But then, there are those reports of single-sex cormorant nests and the killer female mice. Of course crime levels are related to economic opportunity. But then, maybe they are also related to the hyperactivity reported in animals exposed to estrogen-like chemicals. Of course population control is the most important environmental task facing the world today. Of course it is.
When all the results are in, I strongly suspect, not much will remain of the thesis of this book. A corollary of Murphy's Law applies to most scientific warnings of universal disaster. Anything that can go wrong, will go wrong, as we all know. However, for any large system that has been in operation for a good long while, the fact that something has not gone wrong yet is evidence that it cannot go wrong at all. If, as the authors tell us repeatedly, the endocrine system is one of the most archaic things about the world's animals, then it cannot be very disaster-prone. After all, estrogen-like chemicals also occur in plants, including most of the world's staple crops. Dioxin is produced by volcanos and forest fires. If a hormonal catastrophe for the whole biosphere were really possible, one suspects that nature would have contrived one by now already.
Of course, as the authors are themselves aware, many of their claims can be neither proved nor disproved, so strictly speaking all the results will never be in. The concerns raised in this book could thus be influential long after knowledgeable people have decided to dismiss them. Like DDT, they could be persistent long after they have no practical use. They thus can easily have significant effects, whether that are true or false. No one who believes this book can continue to think like a social liberal, but social liberals are the core audience for environmentalist anxiety. We may be in for some very odd chemical reactions indeed
Copyright © 1996 by John J. Reilly