Encore post — originally posted in August 2007. Another in a continuing series, showing the errors in JunkScience.com’s list of “100 things you should know about DDT.” (No, these are not in order.) In the summer of 2009, the denialists have trotted this error out again.
Steven Milloy and the ghost of entomologist J. Gordon Edwards listed this as point six in their list of “100 things you should know about DDT “[did Edwards really have anything to do with the list before he died?]:
6. “To only a few chemicals does man owe as great a debt as to DDT… In little more than two decades, DDT has prevented 500 million human deaths, due to malaria, that otherwise would have been inevitable.”
[National Academy of Sciences, Committee on Research in the Life Sciences of the Committee on Science and Public Policy. 1970. The Life Sciences; Recent Progress and Application to Human Affairs; The World of Biological Research; Requirements for the Future.]
In contrast to their citation for the Sweeney hearing record, which leads one away from the actual hearing record, for this citation, the publication actually exists, though it is no longer available in print. It’s available on-line, in an easily searchable format. [I urge you to check these sources out for yourself; I won’t jive you, but you should see for yourself how the critics of Rachel Carson and WHO distort the data — I think you’ll be concerned, if not outraged.] The quote, though troubled by the tell-tale ellipses of the science liar, is accurately stated so far as it goes.
The problems? It’s only part of the story as told in that publication. The National Academy of Science calls for DDT to be replaced in that book; NAS is NOT calling for a rollback of any ban, nor is NAS defending DDT against the claims of harm. The book documents and agrees with the harms Rachel Carson wrote about eight years earlier.
Milloy (and Edwards, he claims), are trying to make a case that the National Academy of Sciences, one of the more reputable and authoritative groups of distinguished scientists in the world, thinks that DDT is just dandy, in contrast to the views of Rachel Carson and environmentalists (who are always cast as stupid and venal in Milloy’s accounts) who asked that DDT use be reduced to save eagles, robins and other songbirds, fish, and other wildlife, and to keep DDT useful against malaria.
First, there is no way that a ban on DDT could have been responsible for 500 million deaths due to malaria. Calculate it yourself, the mathematics are simply impossible: At about 1 million deaths per year, if we assume DDT could have prevented all of the deaths (which is not so), and had we assumed usage started in 1939 instead of 1946 (a spot of 7 years and 7 million deaths), we would have 69 million deaths prevented by 2008. As best I can determine, the 500 million death figure is a misreading from an early WHO report that noted about 500 million people are annually exposed to malaria, I’m guessing a bit at that conclusion — that’s the nicest way to attribute it to simple error and not malicious lie. It was 500 million exposures to malaria, not 500 million deaths. It’s unfortunate that this erroneous figure found its way into a publication of the NAS — I suppose it’s the proof that anyone can err.
This error, “500 million deaths,” crops up in several publications after it was originally made near the end of the 1960s; honest researchers would get a good copy editor who would do the math and realize that 500 million people would not have died from malaria had there been no control at all, since 1939, when DDT was discovered to have insecticidal properties. Were Milloy and Edwards making a good faith case, I’d excuse it; but Edwards was a scientist and should have known better, Milloy has been spreading this falsehood long enough he could not fail to know better.
But the actual publication from the National Academy of Sciences suggests other issues that JunkScience.com would rather you not know about.
Importantly and specifically, the National Academy of Sciences is calling for broad research 1.) to avoid the problems that DDT presented (problems which Junk Science denies exist), and 2.) to combat the continuing evolution of the insect pests (evolution which Junk Science also denies), and 3.) to provide insecticides that hit specific targets to avoid the collateral damage of harming helpful insects, other animals and especially predators of the harmful insects (more problems that Junk Science pretends do not exist).
Three pages carry references to DDT in the book, The Life Sciences: Recent Progress and Application to Human Affairs — The World of Biological Research Requirements for the Future (National Academy of Sciences, 1970). This was a study of the state of science in several areas, with a survey of places particularly ripe for research considering human needs in the world. It was a sort of road map of where governments and other funders of research should spend their research monies in order to have the greatest beneficial effects.
The book suggests the need for extensive funding for research in biology over the following decade or two, or four. Were Milloy and Edwards correct that DDT was the panacea lifesaver, one might wonder why DDT was included in the book at all except to note a great success that precludes need for further research. That’s not what the book says at all.
Among the chief recommendations, NAS said research had to focus on rapidly biodegradable, closely targeted chemical pesticides to replace the DDT-style, long-lived, broad spectrum pesticides. NAS recognized the environmental dangers of DDT first and foremost in the introduction and statement of key recommendations:
It is imperative that new, degradable insecticides and pesticides with highly specific actions be devised and that their ecological consequences be understood, as it is imperative that the full ecological impact of the existing armamentarium of such agents be evaluated. Classical dose responses, evaluated only in terms of mortality or morbidity statistics, will not suffice; such data also must include an assessment in terms of modern knowledge of cell physiology, metabolism, and cytogenetics. [see page 11 of the book.]
These are exactly the things Milloy and Edwards ignore. This is a warning that simple toxicity tests on humans are not enough — pesticides need to be tested for downstream effects. That is what Rachel Carson called for in Silent Spring, research to understand the full effects of chemicals we use in the wild. This recommendation from NAS fully recognizes that chemicals like DDT, while they may offer significant benefits, can at the same time be significantly dangerous and damaging.
From the general introduction, the NAS authors point to three specific DDT-related issues. In general, the NAS view of DDT can be summarized like this: ‘DDT produced some great benefits fighting harmful insects, but its benefits need to be balanced against its great dangers and great potential for long-term damage. DDT is the poster child for beneficial chemicals that are also hazardous. We need to understand all the dangers as well as some of the benefits, in order to make wise decisions on chemical use. In the interim, where we have gaps in our knowledge, we should be careful.’
By carefully selecting only part of a statement by the NAS in one of the three areas of research, and leaving out all the qualifying statements, Milloy and the late Edwards misrepresent what NAS said. NAS was not calling for greater use of DDT. NAS was not calling for continued use of DDT. NAS was not criticizing any of the bans on DDT usage. NAS was saying we don’t know how great is the danger from DDT, and more study is needed; and use of DDT must be restricted in the interim.
Excerpt 1: Crop research
Increase research in rotating crops, herbicides and pesticides: In a section mentioning the need for alternative treatments, and commending organic methods of farming, on page 182 NAS notes the efficacy of crop rotation, and then talks about the need to have several different tools available to get rid of weeds and insect pests.
Similarly, recognition of the insecticidal properties of DDT in 1939, initially used against insects directly injurious to man, indicated the intelligent application of understanding of insect physiology, entomology, pharmacology, and the arts of the organic chemist could prevent crop destruction by insects. To date, the use of 2,4-D has increased yearly even though it has been replaced in part, and DDT is being withdrawn because of concern for its potentially adverse effects on man, transfer to the general environment, prolonged persistence, destruction of beneficial insects and possibly other wildlife, and stimulation of resistance in the target insects. These are now matters of broad general concern, and it is regrettable that public decisions must be made on the basis of our limited knowledge. But these compounds paved the way for modern agriculture. Without their equivalent, modern intensive agriculture is not possible, and, just as the continual breeding of new crop strains is imperative, so too is a continuing search for effective herbicides and pesticides, optimally with specific effects on offending organisms, degradable in the soil and nontoxic to man and animals. Attainment of these goals will require continuously increasing understanding of plant and insect physiology and life cycles.
Control of undesirable species by biological means is, in many ways, the most attractive possibility for future exploration. The notion is by no means new; attempts at such control began late in the nineteenth century. Indeed, some 650 species of beneficial insects have been deliberately introduced into the United States from overseas, of which perhaps 100 are established. These are now major factors in the control of aphids and a variety of scale insects and mealybugs. More recently, microbes and viruses have been considered for these purposes, a few of which are being used; for example, spores of the bacterium B. thuringiensis are used to control the cabbage looper and the alfalfa caterpillar. Some insects have been utilized for control of weeds — e.g., prickly pear in Australia and the Klamath weed in the western United States — while a combination of the cinnabar moth and the ragwort seed fly is required to keep down the population of the toxic range weed, the tansy ragwort.
There is no ringing endorsement for bringing back DDT, but rather a much more sophisticated understanding demonstrated that a variety of tools, some chemical and some living, need to brought to bear in agriculture and health — coupled with a clear understanding that non-beneficial effects need to be studied and understood, for all attempts to control pests for crops, and threats to humans. This is quite contrary to the general tone of Milloy’s and Edwards’s list, and far beyond the misleading snippet they offer.
Near the end of that first paragraph, the NAS call for pesticides that are pest specific, rapidly degradable once released, and nontoxic to humans and other beneficial creatures, targets and shoots directly at DDT, which is non-specific, long-lived in the soil, and toxic to almost everything.
That’s just the first of the three mentions of DDT.
Excerpt 2: Industrial technologies – Pesticide research
The second mention is in a discussion specific to pesticides. The NAS panel recommends research to find safe, short-lived alternatives that target specific pests. DDT is a long-lived toxin that has broad targets. This is a very long entry, but unlike the JunkScience.com guys, I think accuracy is more than one quote ripped out of context; in context, you see that NAS is not defending DDT as a safe, panacea against malaria.
I quote from the NAS publication at length, below; I want you to see that NAS is not contradicting Rachel Carson in any way; in fact, NAS is paying homage to Carson, adopting her calls to action in research and development, while updating the science which showed, in 1969, that Carson was right more than anyone could have known. Because it’s a long quote, I’ll put it in a different color, not boxing it where the formatting gets out of hand:
[Beginning on page 213]
As noted earlier, the properties of DDT and 2,4-D inaugurated a new era in management of our living resources and gave rise to a new industry. Each touched off a wave of research that continues to the present, seeking newer compounds that are species-specific, safe, and degradable. For the moment, the use of such compounds is indispensable; until superior means and materials are found, these compounds are essential to the success of our agriculture, while assisting in maintenance of our woodlands and protection of our health. It is the scale of this use, rather than their intrinsic toxicity, that has properly generated public concern over the effects of these chemicals on the public health. In 1966, total production of all pesticides in the U.S. was 1,012,598,000 pounds.
The rapid increase in use occurred because new pesticides have been developed that control hitherto uncontrolled pests, and broader use of pesticides in large-scale agriculture has increased crop yields significantly. Current trends in crop production involving large acreages, greater use of fertilizers, and intensive mechanized cultivation and harvesting offer particularly favorable opportunities for insect pests and would result in large crop losses to these pests unless control measures were applied.
The increased number of new pesticides in part reflects a second generation of pesticides with more appropriate persistence for economic control of specific pests, more complete control of the pest, less hazard for the applicator, or less hazardous residues on the crop. An additional impetus to the development of the pesticides comes from the fact that many insect pests have developed resistance to the older pesticides. The development of pest resistance does not necessarily entail the development of more dangerous pesticides; the new agent need only be chemically different to overcome resistance. The continuing search for new, more nearly ideal pesticides requires the joint effort of research teams composed of organic chemists, biochemists, pharmacologists, physiologists, entomologists, and botanists. The effort is managed much like the development of new drugs, each chemical entity being tested in a “screen” of a variety of insects.
About 73 percent of the total insecticide usage is in agriculture, and about 25 percent is used in urban areas by homeowners, industry, the military, and municipal authorities. The remaining 2 percent is applied to forest lands, grassland pasture, and on salt and fresh water for mosquito control. Over 50 percent of the insecticide used in agriculture is applied to cotton acreage alone.
When insect-control measures are not used in agriculture, insect pests take 10 to 50 percent of the crop, depending on local conditions. Losses of this magnitude are not readily tolerated in the United States in the face of a rapidly increasing population and a concomitant decrease in agricultural acreage. In this sense, the use of pesticides might be deemed essential at this time for the production and protection of an adequate food supply and an adequate supply of staple fiber. While alternative methods of pest control are under investigation and development, they are not yet ready to displace completely the chemical pesticides, and it appears that a pesticide industry will be required for some years to come.
Pesticides have been tremendously effective, but individual pesticides, like sulfa drugs and antibiotics, tend to lose their effectiveness as species resistance to them develops. Hence, there will be a continuing search for new pesticides as long as pesticides are considered to be required for the economy or the public health. This search will require the continuing participation of able biologists. As with drugs, new pesticides, optimally, should be selectively toxic for specific pests, rather than broadly toxic against a wide variety of pests with serious side-effects on nonpest species. Broad-spectrum pesticides affect an essential enzyme or system common to a wide variety of pests. A selective pesticide, on the other hand, either should affect an essential enzyme or system peculiar to a particular pest or should be applied in such a way that only the particular pest gains access to it.
An interesting example of a selective pesticide is the rodenticide norbormide, which is highly toxic for rats, particularly for the Norway rat. By contrast, the acute oral toxicity of norbormide for other species is much lower, the lethal dose for a great variety of birds and mammals, per kilogram of body weight, being more than 100 times greater. The mechanism of the selective toxic action of the norbormide for rats is not yet elucidated.
Achievement of target specificity requires a sophisticated knowledge of the anatomical, physiological, or biochemical peculiarities of the target pest as compared with other pests or vulnerable nonpests; a pesticide may then be developed that takes advantage of these peculiarities. This is obviously not easy to accomplish, and norbormide may prove to be unique for many years. An alternative is the introduction of a systemic pesticide into the host or preferred food of the target pest. Other pests or nonpests would not contact the pesticide unless they shared the same host or food supply. As an example, a suitable pesticide may be applied to the soil and imbibed by the root system of a plant on which the pest feeds. The pest feeding on the plant then receives a toxic dose. The application of attractants or repellents (for nontarget species) would increase the selectivity of the systemic pesticide. The use of systemic pesticides on plants used for food by humans or domestic animals poses an obvious residue problem.
There has been a strong public reaction against the continued use of pesticides on the grounds that such use poses a potential threat to the public health as well as being a hazard to wildlife. Careful investigations have so far failed to establish the magnitude of the threat to the public health; i.e., there are as yet few if any clear-cut instances of humans who have suffered injury clearly related to exposure to pesticides that have been used in the prescribed manner. Report No. 1379 of the 89th Congress (July 21, 1966)* concluded:
The testimony balanced the great benefits of disease control and food production against the risks of acute poisoning to applicators, occasional accidental food contamination and disruption of fish and wildlife. . . . The fact that no significant hazard has been detected to date does not constitute adequate proof that hazards will not be encountered in the future. No final answer is possible now, but we must proceed to get the answer. (Italics ours [NAS]).
Failure to establish such hazard does not mean that it does not exist. There are no living animals, including those in the Antarctic, that do not bear a body burden of DDT. Large fish kills and severe effects on bird populations have been demonstrated. The large-scale use of these agents has been practiced for less than two decades, and use has increased annually until this year (1969). Whereas the anticholinesterase compounds, which have high acute toxicity (and hence are highly hazardous to the applicator), are readily and rapidly degraded in nature, the halogenated hydrocarbons are not. With time, their concentration in the soil and in drainage basins, lakes, ponds and even the oceans must continue to increase, thereby assuring their buildup in plant and animal tissues. Over a sufficient time period, this is potentially disastrous. And should such a period pass without relief, the situation could not be reversed in less than a century. Because of the large economic benefit to the farmer, it is pointless to adjure him to be sparing; unless restrained by law, he will make his judgment in purely personal economics terms. But mankind badly needs the incremental food made possible by use of effective pesticides, and the enormous benefit to public health of greatly reducing the population of insects that are disease vectors is a self-evident boon to humanity. Thus it is imperative that alternative approaches to pest control be developed with all possible dispatch, while we learn to use available pesticides only where they are clearly necessary and desirable and to apply them in the minimal amounts adequate to the purpose.
A recent development in insect-pest control has been the possible use of juvenile hormone. This hormone, normally produced by insects and essential for their progress through the larval stages, must be absent from the insect eggs if the eggs are to undergo normal maturation. If juvenile hormone is applied to the eggs, it can either prevent hatching or result in the birth of immature and sterile offspring. There is evidence to suggest that juvenile hormone is much the same in different species of insects, and analogs have been prepared that are effective in killing many species of insects, both beneficial and destructive. There would, therefore, be great danger of upsetting the ecological balance if juvenile hormone were applied on a large scale.
What is needed, then, is development of chemical modifications of juvenile hormone that would act like juvenile hormone for specific pests but not for other insects. For example, a preparation from balsam fir, which appears to be such an analog, has been identified and is effective against a family of bugs that attack the cotton plant, but not against other species. If it proves possible to synthesize similar analogs specific for other pests, a new type of pesticide may emerge. If this happens, it will be extremely important to explore possible side-effects on other insect species and on warm-blooded animals before introduction of yet a new hazard into the biosphere.
We cannot rest with existing pesticides, both because of evolving resistance to specific compounds and because of the serious long-term threat posed by the halogenated hydrocarbons. While the search for new, reasonably safe pesticides continues, it is imperative that other avenues be explored. It is apparent that this exploration will be effective only if there is, simultaneously, ever-increasing understanding of the metabolism, physiology, and behavior of the unwanted organisms and of their roles in the precious ecosystems in which they and we dwell.
* U.S. Congress. Senate. Committee on Government Operations. Interagency Environmental Hazards Coordination, Pesticides and Public Policy (Senate Report 1379). Report of the Subcommittee on Reorganization and International Organizations (pursuant to S. R. 27, 88th Cong., as amended and extended by S. R. 288), 89th Cong., 2d sess., Washington, D.C., U.S. Government Printing Office, 1966.
Anyone should be able to see from various parts of that excerpt that NAS was not defending DDT as harmless; that instead, NAS was saying that despite its great utility, DDT use needed to be extremely limited, and that substitutes for it needed to be found as quickly as possible — and then, the substitutes need to be researched to make sure they don’t have unintended bad effects, on other species, at other places, at other times.
Excerpt 3: The Great Hazards – Man and his environment
The third excerpt has the money quote — it contains an obvious error of fact, but an error that has been seized upon and trumpeted from one end of the world to the other: The 500 million dead miscalculation. Critics of environmental stewards like to trot this out, sometimes going so far as to accuse Carson and environmentalists of genocide, for the deaths of 500 million people that would have been prevented but for our concerns ‘for a few silly birds.’
I reiterate, the mathematics do not work. If we assumed 5 million deaths to malaria every year for the 20th century, we’d get 500 million deaths. Records indicate total deaths as high as 3 million in some years; since World War II, deaths have averaged about 1 million per year. So, even were it true that DDT bans unnecessarily caused all those deaths (and it’s not true), the total, between 1946 and 2006 would be about 50 million deaths. The “500 million deaths” figure is incorrect by a multiple of 10, at least, in addition to being absolutely in error historically. DDT never offered the realistic hope of eradicating malaria; by 1965, it was already failing where it was applied, and human institutional failures (not environmentalists) prevented its application in places where it might have helped.
The National Academy of Sciences (NAS) discusses hazards from chemistry and biochemistry, in one of its final chapters studying life sciences and their applications to human affairs. NAS authors write about the need to study causes of deaths and how to prevent them (including lung cancer and smoking), and there is discussion on the difficulty of getting clear answers to every question. In a section titled “Man and his environment,” NAS discusses environmental damage: Deforestation, pollution, and animal and plant extinctions. On page 430, there is an example given of supposedly beneficial chemicals turning toxic once released; DDT is the example:
Then NAS discusses DDT:
Large-scale use of pesticides can start a chain in which these substances concentrate in plant an animal tissues and, when ingested, accumulate in the adipose [fat] tissue of the human body. As an illustration of this process, consider the record of Clear Lake, California, where DDD (a breakdown product of DDT) entered the lake at 0.02 part per million (ppm). A year later, its concentration was 10 ppm in the plankton, 900 ppm in fish that eat the plankton, and 2,700 ppm in fish that eat fish that eat plankton. No data are available concerning people who ate such fish.
* * * * *
The effects of these changes in the environment on man himself are not known.
NAS notes that absence of proof of damage should not imply safety, and the article notes that small doses of pollutants, repeated over time, can cause serious health problems.
Until reliable evidence thus obtained becomes available, public health measures designed to minimize exposure to such pollutants are patently advisable. But surely a rule of reason should prevail. To only a few chemicals does man owe as great a debt as to DDT. It has contributed to the great increase in agricultural productivity, while sparing countless humanity from a host of diseases, most notably, perhaps, scrub typhus and malaria. Indeed, it is estimated that, in a little more than two decades, DDT has prevented 500 million deaths due to malaria that would otherwise have been inevitable. Abandonment of this valuable insecticide should be undertaken only at such time and in such places as it is evident that the prospective gain to humanity exceeds the consequent losses. At this writing, all available substitutes for DDT are both more expensive per crop-year and decidedly more hazardous to those who manufacture and utilize them in crop treatment or for other, more general purposes.
The health problems engendered by undesirable contaminants of the environment may also be raised by substances that are intentionally ingested. Only large-scale, long-term epidemiological research will reveal whether the contraceptive pills, pain killers, sleeping pills, sweetener, and tranquilizers, now consumed on so great a scale, have any untoward long-range effects on their consumers.* Man has always been exposed to the hazards of his environment and it may well be that he has never been more safe than he is today in the developed nations. Food contamination is probably minimal as compared with that in any previous era, communal water supplies are cleaner, and, despite the smog problem, air is probably less polluted than in the era of soft coal or before central heating systems were the norm. Witness the fact that jungle dwelling natives of South America exhibit a considerably higher incidence of chromosomal aberrations in their somatic cells than does the American population. But modern man also increasingly exposes himself to the chemical products of his own technologies and has both the biological understanding to ascertain the extent of such hazards and the prospect of technological innovation to minimize them where they are demonstrated. To do less would be improvident and derelict.
* This sentence was written in June 1969. Revelations of the untoward effects of both steroid contraceptives and cyclamates were made public months later.
As presented by the “100 facts about DDT” list, all the qualifiers, warnings, and listed harms of DDT are left off. The numbers cited in the quoted section are in error, and considering that the NAS was calling for research into the harms of DDT, research to replace DDT with chemicals that were short-lived, more carefully targeted by species, and fully researched to avoid the collateral harms DDT caused, it seems dishonest to present that edited quote as an endorsement of DDT. It is no endorsement at all.
And so, it is dishonest to present the quote at all so grossly out of context.
Steven Milloy should strike #6 from his list of “100 things you should know about DDT.”