Rachel Carson is widely credited with kick starting the environmentalist movement following publication of Silent Spring back in 1962. She pointed out the dangers of widespread use of DDT and promoted the idea that synthetic chemicals can cause cancer.Many scientists take issue with the "facts" in her book and they believe that she may have done more harm than good. If you care about scientific accuracy then you must be skeptical about her claims, even if you admire her goals.
Carson was born on May 27, 1907 and last month marked the 100th anniversary of her birth.
For a summary of where she went wrong you might as well start with a recent New York Times article by John Tierney [Fateful Voice of a Generation Still Drowns Out Real Science]. Tierney outlines the case very well and he has attracted a lot of attention by not pulling his punches.
For Rachel Carson admirers, it has not been a silent spring. They’ve been celebrating the centennial of her birthday with paeans to her saintliness. A new generation is reading her book in school — and mostly learning the wrong lesson from it.This is the kind of science journalism that I admire but, as you might imagine, Tierney has come under fierce attack from those people who value superstition over rationalism. Tierney has attempted to deal with those attacks on his website [Synthetic v. Natural Pesticides].
There are many issues here but one of the most interesting is whether the essence of Carson's claim is accurate. Is it true that a large percentage of cancers is caused by synthetic chemicals in the environment? That certainly seems to be the general perception both inside and outside the scientific community.
Does this controversy remind you of the framing debate? It's clear that Rachel Carson used very effective framing in advocating her opposition to chemicals in the environment. The metaphor of a "Silent Spring" being only one of many examples. At the time there may have been many scientists who agreed with her about the dangers of DDT and, by extension, many other synthetic chemicals.
However, it's clear that there were also scientists who disagreed, as John Tierney points out in his New York Times piece. The problem is that once scientists start down the framing pathway they open a Pandora's Box that's very hard to close. I think that scientists have to be very, very, careful about abandoning objectivity and skepticism in order to push a political agenda. Once they jump on the bandwagon it's very hard to jump off if the scientific evidence fails to support the agenda. And that hurts the credibility of science.
17 comments :
Larry
I haven't read the book, so any comment I might make directly upon what is in the book is reliant upon the truth of what others have said. You might, however, like to look at Tim Lambert's take on Tierney's piece:
http://scienceblogs.com/deltoid/2007/06/john_tierneys_bad_science.php
and say whether your reading of Silent Spring and its consequences corresponds more with his than Tierney's - in which case Tierney's piece needs rather less uncritical acceptance?
I can see what you're driving at on the "all synthetic chemicals cause all cancer" claim, and don't know enough about it to know the right answer - although Tierney apparently isn't particularly accurate in his citations; but Tierney's argument that her argument that easing up on DDT was necessary to avoid resistance in the malarial vectors was scientifically unjustified and killed millions, the current denialist talking point has to be claptrap.
I've never read Silent Spring,, but I have read others of the same ilk, and Tierney's criticism seems pretty accurate. Many people from that phase of the environmental movement drew the wrong lesson from Silent Spring, by equating "unlimited pesticide use" with "any pesticide use," and thinking that the latter was as dangerous as the former. It's undeniable that some manmade chemicals threaten both wildlife and man himself -- if you doubt it, ask anyone who's familiar with the Minamata disaster. But it should be possible to use pesticides in ways that control the danger.
"The problem is that once scientists start down the framing pathway they open a Pandora's Box that's very hard to close. I think that scientists have to be very, very, careful about abandoning objectivity and skepticism in order to push a political agenda. Once they jump on the bandwagon it's very hard to jump off if the scientific evidence fails to support the agenda. And that hurts the credibility of science."
Total agreement from this corner.
Larry,
As any plant biologist will assure you (including me), plants rarely want to be eaten and therefore have evolved elaborate secondary metabolic pathways to synthesize deadly toxins to prevent herbivory, even cancer causing toxins. This notion that nothing that is "natural" or "organic" can hurt you is wishful thinking. Plants may not be able to walk around and play golf, but they are masters of toxin biosynthesis. Ironically, some plant defense compounds which deter insect herbivory, such as glucosinolates, actually lower cancer risks in humans (eat your brussel sprouts!). While nicotine, one of the most effective natural pesticides of all time, will kill man and bug alike.
Panic...it's organic.
As a side note, it was recently brought up at a terpene conference whether plants "want" to be cultivated. Is agricultural cultivation the ultimate free ride for plants and their DNA? Is giving up toxin biosynthetic pathways a trade off for having humans sow your seeds, water you, and protect you from insects?
Re Tierney
I would take anything that Mr. Tierney says with a ton of NaCl. Mr. Tierney is a notorious climate change denier and his acceptance of the theory of evolution is wishy washy at best.
It's disappointing to see Larry lining up with the Creationists on this issue. Mosquitoes evolve resistance to DDT, just as Carson warned.
On the day late last month that Rachel Carson would have turned 100 years old I posted a piece on Mode Shift that focused on the surprising failure of the nation’s major environmental organizations to defend the mother of modern environmentalism. The free market right has set out on a deliberate path to diminish Carson, and by extension the American environmental community, as credible in responding to the consequences of industrial technology. The attack on Carson is an important facet of the free market right’s campaign to diminish the reach of local, state, and federal safeguards. And it’s been remarkably effective and destructive. The federal government, for instance, has no strategy for responding to global climate change because of its sympathy to free market assertions that the science of climate change is deeply flawed.
In any case on Tuesday this week John Tierney, an influential free market science writer and columnist at the New York Times, leveled a broadside at Carson in the pages of Science Times. Calling Silent Spring a “hodgepodge of science and junk science,” Tierney accused Carson of using “dubious statistics and anecdotes (like the improbable story of a woman who instantly developed cancer after spraying her basement with DDT) to warn of a cancer epidemic that never came to pass. She rightly noted threats to some birds, like eagles and other raptors, but she wildly imagined a mass ‘biocide.’”
I know Tierney and worked with him at the Times in the early 1990s, when he joined the paper. He’s smart, thorough, and delights in being a contrarian on environmental issues. He wrote a famous piece questioning the value of recycling, essentially saying that recycling wastes more energy and materials than it saves. In another piece for the Times Magazine, Tierney singlehandedly changed the public’s view of Stanford biologist Paul Ehrlich when he reported on a bet that Ehrlich made with Julian Simon, an economist at the University of Maryland. In 1968 Ehrlich published The Population Bomb, which predicted a runaway global population boom (he was right on that) and mass starvation globally and food riots in the United States in the 1980s (he was wrong about that). Ehrlich bet that the prices of five key metals would rise as a result of population increases and scarcity of natural resources. Simon bet that innovation would drive prices down. In 1990, Ehrlich conceded defeat and sent Simon a check for $576.07, the amount that represented the decline in the metals’ prices after accounting for inflation, he reported.
Now Tierney is after Rachel Carson, using as the basis of his critique a 1962 review of Silent Spring in the journal Science written by I. L. Baldwin, a professor of agricultural bacteriology at the University of Wisconsin. Baldwin’s review was the subject of debate as intense at the time as Carson’s ground-breaking journalism. Her assessment of the toxic trail left by pesticides in plants and animals was defended and confirmed then by independent scientists, some of them working at the behest of President John F. Kennedy. And they’ve been reconfirmed time and again in the real world since.
read more at www.modeshift.org
Rachel Carson's 100th birthday remembrance certainly brought out a diversity of viewpoints. Was she a visionary who eliminated toxic chemicals from America's environment, or was she a crack pot whose radical actions are responsible for millions of
malarial deaths?
I hope that the next centennial anniversary of her birthday will put her accomplishments into proper perspective. In a day in which any chemical that could be safely manufactured and used was approved, she pointed out
environmental and human health problems of persistent organic pollutants (POPs)... chemicals designed to kill ... occurring beyond their manufacture and use
points. The process of democracy at its finest allowed the analysis, debate and banning of these chemicals over two decades. There is no other arena in history
where man has reversed a technological course for environmental reasons. Yea
human race!
The use of PCB, DDT, toxaphene, chlordane, heptachlor, Lindane, Aldrin, Dieldrin, hexachlorocyclohexane and hexachlorobenzene were banned in the developed countries because they were suspected of causing cancer or were acutely toxic in the environment. Yea Rachel!
As these bans were pursued in developing countries, argument focused upon malarial vector (mosquito) control. Why? The real battle should have been the
use of DDT in general agriculture. When developing countries banned agricultural DDT, what did they use to control pests? Toxaphene!
Banning DDT on grains only, and overseeing its 'discriminate' use for mosquito control would have avoided the spread of DDT in dangerous quantities and
controlled mosquitoes. The DDT ban fight became a smokescreen for the use of all the other POPs!!
Now toxaphene, probably the most used pesticide on the planet, circulates through the air from its uses in developing countries and pollutes cold, clear waters from the northern Great Lakes to the Arctic. Lake Superior, a lake the size of the state of Maine with depths going to below sea level. Its waters, if spilled over the continental United States would cover the area to a depth of
six feet and is frightfully polluted with foreign toxaphene. Its trout harbor 5 parts per million of toxaphene, ten times the level that would classify them as hazardous waste! This is the legacy of the Green Revolution, the 1960s era export of techology to starving nations.
Arctic polar bear and killer whales are on the edge of survival or decimated by banned pesticides and PCBs. PCBs and pesticides circulate through our air in
hundreds of millions of molecules per breathful quantities, amounts that are now being connected to asthma, diabetes and cancer. Inuit ingest 15X a tolerable quantity of poisons.
Rachel Carson was on the right track. Unfortunately, her work is not complete and the planet is still at risk. Please see coldclearanddeadly.com for more information.
Melvin J. Visser
Author of Cold, Clear and Deadly: Unraveling a Toxic Legacy
Tim Lambert says,
It's disappointing to see Larry lining up with the Creationists on this issue. Mosquitoes evolve resistance to DDT, just as Carson warned.
First, you're making the common error of assuming that anyone opposed by the Creationists should be immune to all criticism.
Second, it is true that insects have evolved resistance to DTT as I said in an earlier posting [DDT Blocks the Voltage-Gated Sodium Channel]. The problem is similar to the resistance of bacteria to antibiotics. In order to combat bacterial resistance to antibiotics it's important to keep taking the antibiotics even when you start to feel better. Similarly, it might have been a good idea to keep spraying with DDT to inhibit further development of insect resistance.
In any case, the idea that insects become resistant to DDT has nothing to do with my objections. I'm worried about the general misconception that it's only synthetic chemicals that cause cancer.
Larry
Having yourself claimed that "Tierney has come under fierce attack from those people who value superstition over rationalism" you rather walked into Tim Lambert's identification of Tierney as a creationist; when you gave unqualified support to Tierney's article, and decided to frame the dispute as a battle between superstition and rationalism, you perhaps miscast Tierney?
As to the suggestion that we should have kept taking the DDT so that resistance didn't evolve, by analogy with antibiotics, doesn't this involve being able to destroy the entire relevant population of vectors before they developed DDT-resistance? This was a forlorn hope, since resistance had already begun to appear, as I understand the history; in which case, the analogy doesn't hold.
The attacks on Tierney in the "blogosphere" that I have seen haven't been about whether synthetics (and only synthetics) cause cancer; they have been about his quotemining and inaccuracy, and his repetition of the claims of the generic denialists that Rachel Carson caused the deaths of millions.
Robin Levett says,
You might, however, like to look at Tim Lambert's take on Tierney's piece: and say whether your reading of Silent Spring and its consequences corresponds more with his than Tierney's - in which case Tierney's piece needs rather less uncritical acceptance?
My main objection to the influence of Silent Spring is whether it's true that synthetic chemicals are causing significant amounts of cancer. I'm glad that Tierney has raised this issue and I'm glad that he has introduced a note of caution into uncritical acceptance of Carson's book. (Some of Tim Lambert's criticism is off base, see the comments on his blog.)
I'm also interested in how one goes about promoting a cause that's related to science. This is a hot issue today, as you know. In order to understand how the process should work it's useful to go back and look at a book like Silent Spring in order to see how accurate it was and whether the dire predictions came true.
With hindsight, was banning DDT justified or not? I don't think the answer is as clear as most people think.
Tim Lambert says,
It's disappointing to see Larry lining up with the Creationists on this issue.
It's disappointing to see Tim refuse to consider an argument for it's own merit as opposed to where it comes from. I have no idea where the Creationists stand on the issue of carcinogens in our environement and I really don't care. I'm quite capable of making up my own mind. If the Creationists agree with me then good for them.
Do you always take the opposite side of whatever argument is proposed by Creationists? That seems irrational to me.
Mosquitoes evolve resistance to DDT, just as Carson warned.
I described the mechanism in an ealier posting [DDT Blocks the Voltage-Gated Sodium Channel]. Did you read it?
The fact that insects were evolving resistance to DDT has very little to do with the main message of Silent Spring. Nobody thinks that DDT should have been banned just because of resistant insects. If that were the reason for banning DDT then we should be calling for the ban of all antibiotics that bacteria have become resistant to.
I'm interested in whether arguments are logical and based on sound science. I'm not a fan of people who drag in irrelevant bits of information in order to support their position or distract from the main point. Tierney does this in his article and so do you on your blog.
Robin Levett says,
Having yourself claimed that "Tierney has come under fierce attack from those people who value superstition over rationalism" you rather walked into Tim Lambert's identification of Tierney as a creationist; when you gave unqualified support to Tierney's article, and decided to frame the dispute as a battle between superstition and rationalism, you perhaps miscast Tierney?
The Creationists do not have a hammerlock on superstitious belief. Unfortunately, there are many in the environmentalist movement who fall more into the superstition camp than the rational camp.
Two days ago, we renewed our membership in Greenpeace. It was a tough call since Greenpeace advocates several positions that I think are based more on superstitious nonsense than on rational examination of the facts. They oppose nuclear energy, for example, while I favor it. And I think some of their stances on what to do about global warming are naive and unrealistic.
On the whole, I support their positions and I even support some of their radial tactics.
I don't automatically assume that everything the environmental movement says is true. I'll hold their feet to the fire just as I criticize Creationists and the IDiots. That's what curmudgeons do. :-)
For love of God, Larry & co., read this:
DDT ban myth bingo
http://timlambert.org/2005/12/ddt-ban-myth-bingo/
Nick says,
For love of God, Larry & co., read this:
DDT ban myth bingo
http://timlambert.org/2005/12/ddt-ban-myth-bingo/
So, what's your point?
My point is that the case against DDT wasn't as strong as we thought it was in the 1960's and it serves as a cautionary note against falling for framing and ignoring the science.
Your point seems to be that there are some very stupid people criticizing Rachel Carson therefore everyone who questions her must also be stupid. Do you want to defend that accusation?
Larry, we don't ban antibiotics because bacteria can evolve resistance. What we do is restrict their use so that there will be less selection pressure. Creationists don't get this, which is why you don't want your doctor to be one.
It's the same thing with pesticides. As Carson put it:
No responsible person contends that insect-borne disease should be ignored. The question that has now urgently presented itself is whether it is either wise or responsible to attack the problem by methods that are rapidly making it worse. The world has heard much of the triumphant war against disease through the control of insect vectors of infection, but it has heard little of the other side of the story - the defeats, the short-lived triumphs that now strongly support the alarming view that the insect enemy has been made actually stronger by our efforts. Even worse, we may have destroyed our very means of fighting. ...
What is the measure of this setback? The list of resistant species now includes practically all of the insect groups of medical importance. ... Malaria programmes are threatened by resistance among mosquitoes. ...
Practical advice should be 'Spray as little as you possibly can' rather than 'Spray to the limit of your capacity' ..., Pressure on the pest population should always be as slight as possible.
Creationists don't get this. This also explains a lot of talk about how DDT could eliminate malaria. They look at its successes in the 50s and 60s and think that it could work like that again when it won't as well as it did because of evolution.
As for natural vs synthetic pesticides, let's see what Carson wrote:
Over the aeons of unhurried time that is nature's, life reached an adjustment with destructive forces as selection weeded out the less adaptable and only the most resistant survived. These natural cancer-causing agents are still a factor in producing malignancy; however, they are few in number and they belong to that ancient array of forces to which life has been accustomed from the beginning.
Evolution comes up again. Who'd have thunk it?
If you are interested in a more detailed response to Ames see Tomatis et al
Larry
I entirely accept your point that scare stories with no basis in fact (on the basis of the science then available) are the wrong way to go about persuading people of the scientific merits of anything and if Carson actually claimed, for example, that someone had "instantly developed cancer after spraying her basement with DDT", as Tierney claims,then that is obviously challengeable. Did she make this claim?
You however framed the issue as one of the quality of Tierney's science journalism - you said you admired his science journalism in this piece - and defined him as a rationalist against a sea of superstition.
On the narrow question of whether Carson was right or wrong on whether DDT (and synthetic chemicals) cause cancer, Tierney could be right or wrong without being on the side of rationalism - after all, a stopped clock has to be right twice a day, but that doesn't mean it is reliable generally. More importantly, you don't know when it is right.
Tierney cannot be considered a rationalist just because he is (if he is) on the right side of the narrowly framed issue of whether synthetics cause cancer (more than "naturals").
As to whether he is on the right side of that issue, Tierney quotes Baldwin in Science, but fails to quote the subsequent article in the same journal that reports the vindication of Carson's science by a panel of Kennedy's Science Advisory Committee. It may of course be that that panel was wholly misguided, and got the science completely wrong - but simply to ignore that vindication was hardly honest.
He also (mis)quotes Ames, but doesn't quote the Tomatis study that Lambert has cited above.
On the wider issue of whether Carson caused the deaths of millions by her activism against DDT, he is on the wrong side; and both the history and the science are against him. That doesn't stop him repeating that particular talking-point; which is how you can work out that he ain't a "rationalist". He gives no consideration whatsoever to the point that banning the agricultural use of DDT - which is what she was arguing for - actually delayed the buildup of resistance in malaria vectors, so that she is arguably the reason why DDT remains effective at all.
DDT may not cause problems in humans, but it most certainly does cause problems in birds -- and perhaps other wildlife.
This has been more than amply documented by scientists at Cornell University (Tom Cade, who did some of the early studies on peregrine falcon population declines) and elsewhere.
One would be hard pressed to argue that the ban on DDT in the US was NOT a good thing.
There are a number of species -- particularly peregrine falcons and bald eagles -- that might not be around today were it not for the ban.
The idea that DDT was banned worldwide from use as a method of mosquito control is simply not true, so arguments that "the ban has led to X number of human deaths" are just so much hogwash.
Anyone who makes such arguments either has no idea what they are talking about or is simply dishonest.
--Jim
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