Raloff, a founding board member of the Society of
Environmental Journalists, is a senior editor of Science News where she has covered
the environment since 1977. Over the past 5 years, she has authored some 30 stories
involving pollutants that appear to mimic hormones.
News stories on environmental threats from hormone mimics abound these days.
Many focus on the potential breast-cancer risks posed by a woman's exposure to
pollutants that function like estrogen. Then there are the reproductive scares.
In certain wildlife populations, females appear to have lost the ability to
successfully reproduce. In others, male animals have been born with feminized
reproductive organs. There are even provocative, though spotty, human data
suggesting that males may be suffering from unusual rates of genital
malformations and testicular cancer, and from unusually low rates of sperm
production. Perhaps most troubling, the proportion of male births appears to be
waning in many industrial countries.
The source of the pollutants suspected of triggering at least some of these
dire effects include common pesticides, plasticizers, fuel additives, and
surfactants. Not only do trace quantities of them lace our air and drinking
water, but some have been detected leaching into our foods--from plastic lined
cans, from plastic coated papers, and from plastic bottles. Many animals,
including various types of prized game fish, including lake trout and salmon,
build up significant stores of these compounds in their edible flesh. Some of
these chemicals even appear to leach directly into saliva from teeth treated
with popular dental sealants.|
Though the story of hormone-mimicking pollutants has been brewing for decades,
even as recently as 5 years ago, only a handful of reporters had begun looking
into it. The vast majority of their brethren wouldn't follow suit for another 3
years--until the publication of "Our Stolen Future, "a book by zoologist Theo
Colborn, biologist John Peterson Myers, and then-Boston Globe reporter Dianne
Dumanoski. Since 1994, Colborn has been on a soapbox arguing that a series of
disturbing and related trends suggest an environmental pandemic may be in the
making--some subtle and malign reproductive impairment throughout the length
and breadth of Earth's animal kingdom. Initially, she ascended that soapbox
only in the supportive company of fellow biologists. Gradually, Colborn became
more outspoken about her fears, catching the attention of Congress, U.S.
regulatory agencies, and captains of industry. Then, with "Our Stolen
Future"--and the news blitz it evoked throughout respected major media
leaders--she and her co-authors carried her chilling concerns to the general
public, much as Paul Brodeur's" Zapping of America" brought the formerly arcane
subject of electromagnetic fields to public attention.
Our "Stolen Future" offered solid background on the secret life of our bodies'
endocrine system--and made for surprisingly good drama. Anecdotes and
personality profiles humanized the science of our environment's hormonal
threats to wildlife and its stewards. But even when the book debuted in March
1996, most of the events it portrayed were quite dated. Moreover, much of the
research that it described may ultimately prove misleading. Indeed, that's the
nature of science.
Even today, research on endocrine disrupters remains in its infancy. As a
result, the trends portrayed by news articles must necessarily be sketched from
a remarkably small number of data points. Such a paucity of data leaves
reporters or book authors free to extrapolate broadly on what the few, early
findings suggest. As a field develops, however, it traditionally constrains the
boundaries of what is real--or realistic.
So where today we are questioning to what extent estrogen-mimicking pollutants
may reduce sperm counts in men, we might one day learn that only three of the
dozens of "man-made" estrogens to which we are exposed employ a mechanism that
can affect human sperm production. Or we might find out that any of these
agents can affect sperm, but only if a man's mother had been exposed to them on
day 17 of her pregnancy. Or only if the fetally exposed man smoked during his
teen years. Or faced exposure to these "hormones" through the skin. Or...
You get the point; the probability of any serious risks may be highly
circumscribed. Which is why it's exciting to write about these issues
today--while they're still so deliciously appalling, and nobody has proven that
even the most outlandish prospects are categorically impossible. A few
individuals have begun suggesting that they might be, however. Gina Kolata in a
March 1996 New York Times piece, for instance, quoted scientists who argued
that concerns about hormone mimics must be considered premature until follow-up
data demonstrate not only how pervasive and potent such agents are, but
sciJanalso whether the initial studies were conducted appropriately. About the
same time, a related story in the Washington Post by Rick Weiss and Gary Lee
picked up the skepticism, noting that science "is better at scaring people than
reassuring them." Indeed, they charged that the mix of science, politics and
public relations associated with Colburn's public campaign to put the issue of
"endocrine disrupters" firmly in the public eye "smells undeniably of spin but
is nevertheless difficult to ignore."
Anxious to contribute to that spin have been several chemical industry groups
that have begun funding a few scientists to challenge the concerns that Colborn
champions. To date these critics have largely pointed to those gaps in the data
supporting the frightening trends and to a host of potentially countervailing
effects of chemicals in the environment--ones that might ultimately block
The Competitive Enterprise Institute, based in Washington D.C., took up the
latter crusade in a report it issued at a press conference two days before the
release of Colborn's book. It noted that Mother Nature has imbued some 173
plants (at last count) with hormone mimicking constituents--many of which we
have been eating without harm for millennia. As such, it argued, because the
hormonal alter ego of many pesticides and other synthetic chemicals is nothing
new or unusual, Colborn's campaign to even infer otherwise represents "scare
tactics" that "hit below the belt." Data gaps, and the hazards of offering
speculations to bridge them, plague every fledgling field of science. But the
initial trends that sparse data suggest can be bolstered or responsibly
discredited only by additional research.