Part I: Uses and Abuse of DDT and Dieldrin

BY D. L. GUNN

1 Introduction

Most people are aware, perhaps vaguely, of the existence of modern insecticides and have read in newspapers that DDT has been banned in various countries. Some people regard such compounds as the greatest boon of the age, but others think they art dangerous. Both views contain elements of truth. Only a few specialists know the facts, understand the choices to be made, and see that some choices that have already been made are not scientifically secure or wise.

Background. — There has been widespread organized objection in the U.S.A. to the use of DDT, which was selected as the main target by Rachel Carson, and since then there has been sustained propaganda in the Press. This propaganda has affected popular opinion and legislation and also, I consider, the conclusions reached by committees. I therefore quote examples of it from reputable newspapers : 'inherently dangerous, highly toxic, broad spectrum persistent chemical biocide DDT ...'; 'considered hazardous to birds and marine life ...'; 'Hickel bans 16 pesticides'; quoting C. Wurster, 'DDT has been shown to be a carcinogen ...'; quoting John Thomas of West Virginia 'Impotence down on the farm'; 'DDT found in milk of mothers'. Since DDT is in fact found in many foods, the mainsprings of emotive propaganda – birds, food, cancer, babies, and sex – have been tapped. 'We are dealing with people concerned purely with the profit motive' said Paul J. Burbach' and the campaign broke out into stickers on car bumpers inscribed 'Sue the Bastards'. Burbach continued 'As soon as we knock out DDT we will go after dieldrin and the rest of the persistent pesticides'.

This sort of propaganda has led to several enquiries in the U.S.A., some of them evidently influenced by untrue emotive propaganda rather than objective wisdom, and finally one ordered by the Administrator of the Environmental Protection Agency (EPA) of the U.S. Government, Mr. William D. Ruckelshaus, with Mr. Edmund M. Sweeney as Hearing Examiner. After a very full hearing of all sides of the matter lasting more than six months with 125 witnesses on 80 working days, Sweeney reported to the Administrator in April 1972. In June, Ruckelshaus ordered the general use of DDT in the U.S.A. to cease from the end of December 1972, and allowed only minor exceptions. In support of this order he made statements contrary to the findings of Sweeney's report, statements of an unscientific character, and statements at variance with the weight of evidence presented at the Hearing. The almost complete prohibition of the use of DDT in the U.S.A. was not based on the evidence nor on the balance of advantage to the people. Later, Ruckelshaus did almost the same thing by appointing a committee under R. D. O'Brien to report on aldrin and dieldrin and then ignoring the report. He was later appointed Director of the Federal Bureau of Investigation but did not stay long in that office.

On 16th October 1973, Hearings on aldrin and dieldrin began in Washington, D.C., under Judge Herbert L. Perlman, after 'field hearings' in August, and were still proceeding in August 1974. It will be interesting to see how Ruckelshaus's successor, Russell Train (see ref. 217), reacts to Perlman's report, when it is delivered.

Since 1972, hundreds of thousands of acres of Douglas Fir in Oregon, Washington, and Idaho have been completely defoliated by the tussock moth, formerly controlled by DDT. Some areas have suffered like this for the third year in succession, and are not expected to recover. Similar damage has been done in eastern U.S.A. by the gypsy moth, formerly controlled by DDT (see p. 17). Applications to permit the use of DDT in these cases have failed, and a bill to overcome the EPA ban was placed before Congress later in 1973. Eventually, the public outcry through an organized campaign, led by a vociferous minority, against the damage being done became so great that the EPA Administrator, Russell Train, gave way and allowed the use of DDT against tussock moth just for 1974. It has been stated that he did this lest he be over-ruled by Congress, and lest the EPA be deprived of some of its great powers.

In 1970, the use of cyclamates as sweeteners was prohibited in the U.S.A. on evidence which was regarded by specialists in Britain, and no doubt also in the U.S.A., as totally inadequate and unreliable; nevertheless, Britain followed the U.S.A. in prohibiting its use. It now seems that when the experiments have been repeated in several countries, not one of them has confirmed the results upon which the ban was based. Perhaps the prohibition will shortly be removed, and perhaps some revision of the rules about DDT will ensue.

The decision of Ruckelshaus to forbid most uses of DDT in the U.S.A. was taken to the U.S. Court of Appeal in December 1973. The three judges decided that they need not undertake the 'time-consuming and difficult task of weighing the evidence' upon which Ruckelshaus based his decision. The Court said that all that was required was 'substantial evidence', 'to support a conclusion', apparently irrespective of other information that might completely undermine the original evidence and therefore the conclusion. Thus the judgment quotes that 'substantial evidence is something less than the weight of evidence and the possibility of drawing two inconsistent conclusions from the evidence does not prevent an administrative agency's finding from being supported by the evidence'. Further, the Court stated that although other 'evidence might be sufficient to have allowed the Administrator to have decided the other way and permit DDT to continue', that possibility did not exclude substantial evidence to support the order to stop the use of DDT.

Amongst the items of 'substantial evidence' quoted on p. 12 of the Court Judgment are human hazards from 'carcinogenicity and mutagenicity of DDT'. No public authority on cancer considers that DDT has this hazard to man (see pp. 27, 63–66, 73) and, as far as I know, no trained scientist considers that it is mutagenic (see p. 67).

Surely this is the sort of judgment that brings the law into disrepute. A revulsion against the improper extrapolation of information and the weighing of fears more heavily than of needs may spread from the recent quick decision to permit the Alaska pipe-line to be laid after years of obstruction by people more concerned about conservation of wild animals than about human beings.

This subordination of scientific conclusions and of the public good to organized propaganda merits fuller discussion, for what happens in the U.S.A. is likely to affect other parts of the world. It is everybody's business, so a sound basis for forming opinions is required. The present contribution to that purpose is primarily addressed to chemists and biochemists who are familiar with toxicology; but to set the situation into the larger picture, other material has been...