On June 2nd, 1972, William D. Ruckelshaus, Administrator of the Environmental Protection Agency, issued an order effectively ending the agricultural use of DDT in the US.
Thirty-five years later, that order is still the subject of fierce controversy.
One claim often made by proponents of renewed DDT use is that Ruckelshaus’ decision was capricious and unsupported by the evidence — specifically, that he acted in willful disregard of his own hearing examiner’s findings. For example, in a post co-authored with the late J. Gordon Edwards, Steven Milloy states that Ruckelshaus “ignored the decision of his own administrative law judge.”
Milloy’s distortion of the history and science surrounding DDT is shameless, and deserves to be the subject of a separate post. But let’s stick with the Ruckelshaus order for now.
Did Ruckelshaus ignore the conclusions of his hearing examiner? You’d think, since this claim is made so relentlessly by DDT advocates, that we could find the relevant document somewhere on the Web. But it’s not that easy. Ruckelshaus’ order itself is readily available (see below for a more readable copy), but the hearing examiner’s findings … not so much. The document is sometimes cited as “Sweeney, E.M., 1972. ‘EPA Hearing Examiner’s Recommendations and Findings Concerning DDT Hearings,’ April 25, 1972. 40 CFR 164.32.” — which helps a bit, but only a bit, since “40 CFR 164.32″ is just the Federal Regulation governing administrative hearings at EPA. Anyone who offers that to you as an actual cite for the opinion is blowing smoke. A better cite is the one given in the order, viz.: “Stevens Industries, Inc. et al., I.F&R. Docket Nos. 63 et al. (Consolidated DDT Hearings)”. But even that will not get you anything online. EPA does give its Decisions and Orders online, but only back to 1989. A good deal of fruitless searching convinced me that the Sweeney opinion would not be mine with the click of a mouse; it was old-school or nothing. After several weeks, a dozen or so phone calls and the help of some very nice university librarians, I was able to get my hooks on all 173 glorious manually typewritten pages of Edmund M. Sweeney’s “Recommended Findings, Conclusions and Orders.”
Here it is. (56 Mb pdf!) EPA’s librarians indicated that they would not post it online, because of the wretched quality. I’m not so picky. While we’re at it, here is a (slightly) more readable copy of Ruckelshaus’ order.
(UPDATE: See  below.)
The following are some of the more notable things we can observe if we look at both documents:
Did Sweeney’s findings generally support the Petitioners (DDT registrants)?
Yes. Sweeney found no evidence to indicate that DDT causes mutations or birth defects in humans, considered the evidence for DDT’s carcinogenicity in humans to be inconclusive, and, though he found that DDT is harmful to wildlife, he deemed that harm to be outweighed by DDT’s value as a pesticide. Sweeney’s findings of fact are summarized in pages 91-92, and his conclusions of law in pages 93-94. Milloy quotes (#17) part of those conclusions:
The EPA hearing examiner, Judge Edmund Sweeney, concluded that “DDT is not a carcinogenic hazard to man… DDT is not a mutagenic or teratogenic hazard to man… The use of DDT under the regulations involved here do not have a deleterious effect on freshwater fish, estuarine organisms, wild birds or other wildlife.”
That partial quote is misleading. Sweeney also found (p. 92) that
20. DDT can have a deleterious effect on freshwater fish and estuarine organisms when directly applied to the water.
21. DDT is used as a rodenticide.
22. DDT can have an adverse effect on beneficial animals.
23. DDT is concentrated in organisms and can be transferred through food chains.
It is not true that Sweeney found no harm caused by DDT. Rather, he found that, using a “preponderance of the evidence” test, DDT users and USDA had shown that DDT’s usefulness to agriculture outweighed the demonstrated harm.
Did Ruckelshaus ignore Sweeney’s opinion?
No, but he disagreed with substantial portions of it. Ruckelshaus quotes extensively from Sweeney’s opinion, including the findings of fact and conclusions of law noted above. He repeats arguments made by the petitioners, and describes how he differs. Choosing one example:
Group Petitioners and USDA argue that the laboratory feeding studies, conducted with exaggerated doses of DDE and under stress conditions, provide no basis for extrapolating to nature.
They suggest that the study results are contradictory and place particular emphasis on documents which were not part of the original record and the inconsistencies in Dr. Heath’s testimony as brought out during cross-examination. Group Petitioners also contend that the observed phenomenon of eggshell thinning and DDE residue data are tied by a statistical thread too slender to connect the two in any meaningful way.
Viewing the evidence as a total picture, a preponderance supports the conclusion that DDE does cause eggshell thinning. Whether or not the laboratory data above would sustain this conclusion is beside the point. For here there is laboratory data and observational data, and in addition, a scientific hypothesis, which might explain the phenomenon.
This is exactly the kind of language that sent J. Gordon Edwards ballistic (detailed discussion reserved for another post). Then as now, DDT advocates felt that the existence of studies with negative results created enough doubt that a ban could not be justified. Ruckelshaus felt just the opposite — that the bulk of the evidence supported a ban — and explained why. For eggshell thinning, 35 years of research have shown that Ruckelshaus was right. A follow-up report issued in 1975 cited 179 studies related to eggshell thinning alone (pp. 69-81). Today, a quick check of PubMed for “ddt eggshell” turns up 50 papers since 1969, and it is clear from the abstracts that the association of thinning and DDT is well established. Bald eagle populations have rebounded since the DDT ban, so successfully that they are now delisted as threatened, a result accepted matter-of-factly by wildlife biologists as a benefit of the DDT ban.
How did Ruckelshaus’ order differ from Sweeney’s recommendation?
One word: cotton. Sweeney ruled on six separate applications for DDT registration, affirming the cancellations for two, vacating the cancellations for three, and allowing a sixth to start the application process. Two of the cases where Sweeney restored the DDT registration were for public health uses: Wyco’s for treatment of mosquito larvae and Eli Lilly’s for use against body lice. Ruckelshaus permitted both applications, as well as public health use of DDT generally, but required a label restricting it to that use. As to DDT’s application worldwide against malaria (the topic of so much dispute nowadays), Ruckelshaus took pains to say that he was not restricting it:
It should be emphasized that these hearings have never involved the use of DDT by other nations in their health control programs. As we said in our DDT Statement of March, 1971, “this Agency will not presume to regulate the felt necessities of other countries.” (p. 26)
The remaining case in which Sweeney vacated the cancellation of DDT registration, permitting its use, was a biggie: USDA and Group Petitioners (31 users of DDT). These had argued collectively that DDT was “essential” for economical production of various crops and control of pests such as the spruce budworm. Of these applications, by far the most important was cotton production, accounting for at least half of all DDT consumption in the US. Other crops were discussed, with sweet peppers in the Delmarva peninsula used as an example. In his order, Ruckelshaus carved out specific exceptions for several crops where DDT was considered the only acceptable alternative, and said that
… if these users or registrants can demonstrate that a produce shortage will result and their particular use of DDT, taken with other uses, does not create undue stress on the general or local environment, particularly the aquasphere, cancellation should be lifted.
The fact that a few loopholes were left open for a while does not change the fact that Ruckelshaus intended to eliminate use of DDT on crops in the US, and his order did have that effect. Even for the “essential” uses, alternatives were found and DDT was dropped. The largest impact of the order was on cotton production. And this is where it gets even more interesting. One of Sweeney’s conclusions of law (p. 94) was that
13. The use of DDT in the United States has declined rapidly since 1959.
The EPA’s 1975 report gives a table (p. 149) that I’ve represented graphically below.
Although exports, and overall production, continued to rise until 1963, US consumption of DDT peaked in 1959, before any significant restrictions were placed on its use, and declined steadily thereafter. A reasonable person might wonder why that would be. Guess what? The boll weevil and the bollworm were becoming resistant to DDT. Sweeney refers to this fact (p. 86) and observes that
While the evidence convinces me that the use of DDT on cotton is declining and should be reduced as soon as effective replacement means of controlling pests are developed, I do not feel that the evidence to date permits any conclusion to the effect that DDT should be banned for use on cotton at this time.
Ruckelshaus disagreed. With his order, use of DDT on cotton pests became history. The economic impact on cotton growers was significant but far from catastrophic: costs to cotton producers were estimated at $7.75 million nationally, and for consumers at 2.2 cents per capita per year (p. 193).
Even in the one arena where the DDT ban was argued to be unbearably burdensome, its use was already declining, the hearing examiner recommended that it be reduced further in favor of alternative methods, and in the event, the ban’s effects were easily absorbed. Well, then — did it have any impact that we should care about?
Glad you asked.
Returning to Steven Milloy’s DDT FAQ, cited above, we find a pearl. Robert Desowitz’ The Malaria Capers is quoted (#8):
“There is persuasive evidence that antimalarial operations did not produce mosquito resistance to DDT. That crime, and in a very real sense it was a crime, can be laid to the intemperate and inappropriate use of DDT by farmers, especially cotton growers. They used the insecticide at levels that would accelerate, if not actually induce, the selection of a resistant population of mosquitoes.”
That’s right. The 1972 DDT ban did nothing to restrict the chemical’s use against malaria, but had the effect of eliminating the single most intense source of selection pressure for insecticide resistance in mosquitos. As the rest of the world followed suit in restricting agricultural use of DDT, the spread of resistance was slowed dramatically or stopped.
By this single action, William Ruckelshaus — and, credit where it’s due, Rachel Carson — may well have saved millions of lives.
Steven Milloy is invited to add that to the DDT FAQ any time it’s convenient.
 A footnote explains that the post is “largely drawn from materials compiled by J. Gordon Edwards, professor of entomology at San Jose State University.” How much actual collaboration took place, if any, is not stated.
 Technically, it’s not a “decision”, but an opinion stating “recommended findings, conclusions and orders.” A fine point, to be sure, but it makes a difference.
 “It has been estimated that two-thirds of the DDT that is used in the United States is used in agriculture, and that 75% of the DDT that is used on agricultural crops is used on cotton.” (Sweeney, p. 83). According to the 1975 report, cotton’s share had increased to 80% by 1971-1972.
 UPDATE: EPA has now posted its DDT archives, complete with the Sweeney opinion, here. You can now download a better-quality copy of the opinion at a fraction of the size, so do that. If my copy is adding no value, I’ll probably take it down eventually. I see that the EPA page was last updated September 25th, roughly a month after this post. I’d like to think that my prodding was a factor, but there’s no way to know.
(Hat tips are due Ed Darrell, for the best historical coverage, Bug Girl, for the best scientific coverage, and Tim Lambert, for the best overall coverage of this issue.)