The Mismeasure of Man

The environmentalist assault on chlorine has taken a recent turn. Organochlorines, we are now told, not only cause cancer, they are capable of altering human and animal sexuality as well. For instance, environmentalists blame organochlorines such as dioxin for altering the sexual characteristics of fish. Other compounds are blamed for (no joke) creating lesbian sea gulls, and shrinking alligators' penises.

Perhaps the most potent weapon in the anti-chlorine activists' arsenal has been the charge of falling sperm counts. The alarm over chemically-induced male infertility was prompted by a 1992 study from Copenhagen that claimed to show that sperm concentration per unit volume had fallen by over 40 per cent from 1940 to 1990. A year later, one of the authors of the study, Niels Skakkebaek, penned a follow-up piece with Richard Sharpe of the British Medical Research Council Reproductive Biology Unit in Edinburgh, Scotland, in the journal Lancet. The duo speculated that fetal exposure to synthetic estrogens may be the prime suspect in the sperm count crisis.

Unsurprisingly, the Lancet article prompted a barrage of alarmist media reports. The BBC aired a documentary entitled "The Assault on the Male;" here in the U.S., Connie Chung devoted an installment of her now-defunct investigative show, "Eye to Eye," to the plight of infertile men under chemical siege. As scientists have noted, however, the original study — a meta-analysis of 61 studies on falling sperm counts — suffered from numerous statistical and methodological shortcomings.

First, the Danish researchers included studies irrespective of their sample size, many of which were so small that they would not normally be considered admissible evidence. In an editorial for the British Medical Journal, Stephen Farrow of Middlesex University's Health Research Center noted that one study was of seven men; 11 others were of fewer than 20 men; and another 29 were of fewer than 50 men. These were given greater weight than they deserved, Farrow wrote, through the misapplication of statistical tests.

After investigating the Skakkebaek data, a different team of researchers showed that nearly all of the alleged decreases could be explained by the changing definition of a normal sperm count over the past 50 years. They concluded in a study also published by the BMJ that "The original evidence does not support the hypothesis that the sperm count declined significantly between 1940 and 1990."

Furthermore, critics who reanalyzed the data have challenged the timing of the decline reported. As reproductive specialists Anna Brake and Walter Krause of Philipps University in Marburg, Germany explained in a letter to the BMJ, 48 of the studies used in the meta-analysis were published since 1970 — accounting for 88 percent of the men studied. These studies actually showed a slight increase in sperm counts. Krause and Brake concluded that "care should be taken when discussing a causal relation with environmental factors."

The plea for caution fell upon deaf ears at Greenpeace headquarters. Seizing on the Skakkebaek findings, the environmental group launched a new advertising campaign that publicized the alleged environmental threat to man’s virility. "You’re not half the man your father was," the ads taunted.

The Skakkebaek findings have also been touted by the authors of Our Stolen Future, the self-described "sequel" to Rachel Carson's Silent Spring. This book warns of "reports that human sperm counts have plummeted over the past half century, a blink of the eye in the history of the human species." Researchers that are skeptical of the sperm count decline are compared to those who challenged the initial scientific findings linking chloro-flourocarbons to depletion of the ozone layer.

Skepticim is warranted, Greenpeace and Our Stolen Future notwithstanding. Responsible scientists have assailed environmentalists for exploiting the data. As one set of outraged researchers argued, "there is no conclusive evidence" for blaming exposure to estrogenic chemicals in the environment for falling sperm counts or shrinking penises. The hypothesis "is based on evidence too limited to allow firm conclusions to be drawn. It is premature to call for a ban on these or any other chemicals before more research is done. They are misrepresenting this research. They are taking something which is a clearly stated hypothetical link and calling it fact." The identity of these critics? None other than Neils Skakkebaek and Richard Sharpe, whose research prompted the sperm scare in the first place.

There is certainly evidence that some chemical compounds — both natural and manmade — are capable of impacting human and animal reproductive systems. In theory, this could impact human fertility. To date, however, the scientific evidence does not support such a claim. The charge that synthetic compounds are sterilizing men, like so many of the charges leveled by environmental activists over the years, simply does not hold up to scrutiny.

Michelle Malkin and Michael Fumento are, respectively, the 1995 and 1994 Warren Brookes Fellows in Environmental Journalism. They are the authors of the CEI study Rachel’s Folly: The End of Chlorine from which this article is adapted.