are vacant; and (3) altering competition within the treated area. The general pattern of plant succession in Southeast Asia following defoliation or other similar disturbance includes first stage dominated by grasses and weeds, followed within a year by a shrub stage, this in turn rapidly replaced by fast growing trees, eventually reaching the previous condition.

2. Long-term effects on wildlife may be beneficial or detrimental

In many temperate zone areas, herbicidal treatment of forest has improved the wildlife habitat and favored animal production through increases in wildlife food plants.

Destruction or modification of the habitat may greatly influence fauna that are rare or in danger of extinction. The increase in grasses and shrubs following defoliation may cause shifts in animal populations depending upon their food requirements. Animals such as the rare kouprey, an ancestral bovine, may be favored by the increase in bamboo and grasses following defoliation.

The many unknown factors, including feeding, habits of many indigenous animals, makes specific effects on wildlife difficult to predict.

3. Herbicides now in use in Vietnam will not persist at a phytotoxic level in the soil for long periods

Under the average temperatures and rainfall in Vietnam, it is reasonable to expect that orange will be dissipated quickly. In temperate regions, 2,4-D persists for about one month regardless of the rate of application, 2,4,5-T may remain in the soil for three months. Picloram, a component of the herbicide white, is persistent in soils but will tend to leach to depths of two to four feet under average rainfall and soil conditions. Cacodylic acid or blue presents no phytotoxicity problem from soil residues. Crops can be planted within a few days after spraying at heavy rates without risk of injury. More rapid disappearance could be expected in the tropics because of the high rainfall and soil temperature. 4. The possibility of lethal toxicity to humans, domestic animals or wildlife by use of herbicides is highly unlikely

Direct toxicity hazard to people and animals on the ground is nearly nonexistent. All three herbicides used present no hazard from skin absorption. If wildlife are affected, it would be from removal of habitat or food rather than direct toxicity.

Extensive studies of toxicity of 2,4-D and 2,4,5-T have shown that the risk of human and animal toxicity from these herbicidal components of orange is very, very low. Applications of orange and white along rivers and canals or even the spraying of the water area itself at rates used in Vietnam for defoliation is not likely to kill the fish in the water.

Data on toxicities of picloram and white show that at recommended rates there is little direct toxicity hazard associated with their use. Cacodylic acid, unlike trivalent arsenic compounds, has a very low oral toxicity.

The report indicates that food produced from the land treated with herbicides will not be poisonous or significantly altered in nutritional quality.

Residues of orange, white and blue will not accumulate in fish or meat products to the point where they will be harmful to man.

5. Unlike many insecticides, herbicides seldom persist in animal or insect tissues Transfer of herbicides to the next animal in the food chain on defolianttreated areas is negligible. Most herbicides, including all of those used in Vietnam, are readily excreted and do not accumulate in the animal body.

6. Indirect effects of herbicides resulting from destruction of aquatic vegetation may produce changes in the biota of the aquatic environment

Direct toxic effects on fish and aquatic organisms are negligible. Destruction of specific plants used for fish foods will lead to changes in the food chain of the aquatic ecosystem. Application of herbicides to remove floating aquatic weeds will provide important benefits because their presence depletes the oxygen content of the water.

B. Areas of inquiry in which reliable judgments could not be made in this study were as follows:

1. Effects of spraying 2,4-D and 2,4,5-T esters on water quality

One of the important problems from the standpoint of effect of herbicide residues and the persistence of these residues in the ecosystem involves water sup

plies. With increasing use of herbicides on noncropland, it is important to evaluate their persistence in surface water. For example, the herbicide, 2,4-D, is degraded rapidly in surface water when applied at amounts up to 5 pounds per acre. Oregon studies showed that detectable quantities of herbicides were found in virtually all streams sampled after helicopter applications of 2,4-D and 2,4,5-T at 2 pounds per acre on forested areas, but persistence was measured by days.

No firm conclusions could be drawn with respect to effect on water quality in Vietnam. Direct toxic effects would be quite unlikely.

2. Effects of defoliation on mammals and birds in danger of extinction Whether the application of herbicides will be a critical point in survival of rare species is not known.

3. Effects of defoliation on climate and the hydrologic cycle

The climate, microclimate, weather and hydrologic factors of an ecosystem must be considered in any attempt to assess the ecological consequences resulting from indirect effects of herbicide treatments. The relative effects on these factors under tropical conditions would probably not be significant.

4. Effects of defoliation on soil erosion

The use of herbicides on the forests and rangelands of the United States for vegetation control and management has generally been effective in reducing soil erosion by comparison with mechanical methods of vegetation control and other techniques. On sagebrush lands of the West the proper application of herbicides decreases both wind and water erosion hazards. In the Great Plains area, the use of herbicides to achieve chemical fallow has also reduced soil erosion.

In tropical areas removal of forests on lateritic soils may result in modification of the soil to an impervious laterite rock. No evidence has been obtained that such irreversable changes have resulted in areas in Vietnam subject to defoliation. Observers in Vietnam have indicated that the vegetation succession following defoliation in tropical forest is one in which grasses rapidly cover the ground in dense stands followed by rank growth of weeds and vines which are effective in minimizing soil change.

COLUMNS RELATING TO CHEMICAL AND BIOLOGICAL WARFARE BY JOSHUA LEDERBERG

[From the Washington Post, Sept. 24, 1966]

A TREATY PROPOSAL ON GERM WARFARE

(By Joshua Lederberg)

(The author is Professor of Genetics at the Stanford University School of Medicine, and a recipient of the Nobel Prize for Medicine in 1958.)

On Sept. 19 a distinguished group of my scientific colleagues released the text of a petition to President Johnson concerning U.S. policy on biological and chemical warfare. They point to the encouragement for the wider commitment to these weapons that our own actions in Vietnam might generate.

According to news reports, we are making extensive use of defoliating chemicals not only against forest cover but also against crops purportedly available to the Vietcong. At some times, tear gas has also been used in military and occupation missions.

The United States has vehemently denied the military use of any biological weapons or of any lethal chemical weapons. However, research on these weapons has continued through and from World War II The Army has a wellknown research facility at Fort Detrick, Md., and a testing station at Dugway, Utah. The aggressiveness with which these activities have been publicized may be laid to intra-service competition for funds to expand a line of work whose actual military utility is highly controversial.

CBR (Chemical, Biological, Radiological Warfare) can easily evoke a highly emotional response, attracting the most vehement emotions on the inhumanity of war. The focus on boycott demonstrations against napalm production shows this; aircraft manufacture or steel production would be far more consequential to the roots of military homicide. The petitioners do not allude to the specific inhumanity of CBR, but it is undoubtedly involved in the stringency of their reactions.

Can we be "rational" about the inhumanity of one class of weapons as against another? It is hard to imagine more inhuman methods of homicide than explosion or suffocation in a collapsed building or starvation, the most widely practiced techniques of contemporary warfare. Humanitarian opposition to CBR is altogether irrational, except as it is directed to war itself. It can be argued, however, that man's proclivity to warfare must be contained through his social institutions, and any breakdown of traditional limitations in the way war is practiced is one more step of degradation of the species.

The petition suggests that minor uses of CBR will lead to escalation. However, since tear gas is already rationalized for other social purposes, the lumping of Chemical, Biological and Radiological warfare may be especially confusing, and could exacerbate the chances of escalation. Biological warfare should be carefully set apart, particularly for the initiative in international negotiations, for several reasons:

Its development is closest to medical research, therefore conveys the most intense perversions of the human aims of science.

It is the most dubious of military weapons.

Its effects in field use are most unpredictable, with respect to civilian casualties, and even retroactive on the user.

The large scale deployment of infectious agents is a potential threat against the whole species: mutant forms of viruses could well develop that would spread over the earth's population for a new Black Death. Chemical weapons, however potent, at least do not produce equally or more virulent offspring.

One approach to the control of biological warfare should be a nonproliferation treaty. Biological warfare development is within the potential resources of the smallest nations, and the weapons liable to the most irresponsible use. On the other hand, no vital interests of one nation are now committed to biological warfare: the powers can afford to limit their sovereignty in this area.

A nonproliferation treaty in this area could be a constructive precedent for other areas of arms control; the more narrowly it is defined the greater the likelihood of its adoption.

The treaty could dedicate all biological and medical research to human welfare. In this light, no research on living organisms could be classified. M.D.'s and Ph.D.'s in life sciences would be registered and expected to report periodically on their current research activity to an international organization. Ideally, these registrants should have the right of free travel, if necessary, for the purpose of reporting violations of the treaty. Special provisions are needed for proprietary interests, e.g., the drug industry, but with stringent time limits set for confidentiality of its information. A world data center for life sciences would have many human benefits, in addition to centralizing the surveillance of treaty obligations.

The future of the species is very much bound up with the control of these weapons. Their use must be regulated by the most thoughtful reconsideration of U.S. and world policy.

[From the Washington Post, Mar. 30, 1968]

CONGRESS SHOULD EXAMINE BIOLOGICAL WARFARE TESTS

(By Joshua Lederberg)

The ethics of biological experimentation has become a subject of legislative interest in the last few months. This concern started from the publicity given to important advances like heart transplantation. It may now have a much more pointed application to experiments laden with global hazards, conducted in great secrecy, and outside the reach of any tradition of medical ethics. The news that provokes this observation comes from Skull Valley, Utah, near the Dugway Proving Grounds of the Army Materiel Command.

A few thousand sheep have died, suddenly and mysteriously. At this writing. the Army is still investigating the incident; earlier news reports quoted some military spokesmen as quick to deny the possibility that some experiments at Dugway had misfired.

An independent investigation is clearly out of the question in such a securitysensitive area. Under these circumstances, it is difficult to see how a credible account can be obtained, whatever the facts.

If the incident had no ramifications beyond the accidental release of a potent chemical weapon; if the hazard were limited under any circumstances to a few thousand people, it might be put down to the fortunes of war. The incidental risks would not be fundamentally different from those of high-explosive munitions, casually transported on a large scale.

Sadly, one of the insanities of the chase after military security is a world-wide competition in research and development on biological warfare. Because the Russians or the Chinese might be investigating exotic bacteria and viruses, the argument goes, we must do the same in self-defense. And of course the Russians and the Chinese have exactly the same reaction to our own secret programs.

These activities are aimed at practicing the large-scale deployment of the most contagious enemies of man that he can discover or invent. Our personal security must then depend on the depth of the technical competence of the men responsible for the research. This is impossible to judge from outside the secrecy barrier. However, it is almost certain that the technicians willing to work in this area are self-selected for peculiar nonchalance about it. Who else would? Without other objective surveillance, we have to be unforgivingly harsh in our judgment of mistakes and leaks that do come to public notice.

Is anyone competent enough to play with these matches, which are designed to ignite "controlled pestilence"? According to a paper in the December 8, 1967, issue of Science magazine, the American Public Health Association has a file of 2700 cases of virus infections contracted by workers in medical laboratories. These included 107 fatalities. This file is probably not complete; we have no way of

knowing the completeness with which such cases are reported from military research laboratories. I do know that one of my late colleagues in microbial genet ics died of a plague infection contracted in the British laboratories at Porton. And he dies in town.

In the midst of the global arms race, it would be futile to demand a unilateral abnegation of research on biological weapons. A Congress interested in biological ethics should, however make insistent demands for efforts, which do not now exist, to find formulas for international control of species-suicidal research. For his own personal security, every Congressman should also seek his own assurance-less readily available to the common citizen-that the internal surveillance of experiments with contagious weapons is prudent enough to suit him and his family.

[From the Washington Post, Aug. 17, 1968]

SWIFT BIOLOGICAL ADVANCE CAN BE BENT TO GENOCIDE

(By Joshua Lederberg)

The phrase "germ warfare" evokes a moral revulsion which is not strictly justified. War is already awful; how nice it would be to bypass its blood and guts and evoke some clean, almost symptomless disease instead.

From a military standpoint, the ideal agent for BW (biological warfare) would be a completely nonlethal but highly contagious virus that merely stupefied its victims for a few hours or days and for which the good guys had a reliable antidote or preventive antibody. This hypnovirus is a logically plausible ideal, just as is the thought of using mind-altering drugs as chemical warfare agents. (LSD was in fact studied by the U.S. Army long before the hippies discovered it.)

Having the hypnovirus would, however, make very little difference to the maneuverings of the great powers, with their highly automated nuclear missile systems. Could we persuade the Kremlin to exclude biological attack from the threats it intends to retaliate against? The impact of hypnovirus on smallcountry politics, and on the "policing" of the world by the major powers, would be another matter, one that deserves a more leisurely discussion.

For the moment, hypnovirus is a pipedream. Most BW research is claimed to be defensive. That is, it seeks to anticipate the worst horrors an enemy might develop, then beat him to it so as to know how to defend the population. Needless to say, there is no more ingenious device to ensure the rapid escalation of offensive capabilities.

Whether work is actively proceeding in BW laboratories on producing a hypnovirus, I do not know. They have, however, published abundant reports showing their preoccupation with plague, anthrax, rickettsia, tularemia, encephalitis virus and other equally unpleasant and highly lethal disease agents.

The most chilling thought is that GW research has only just begin to tap the potential offered by chemical genetics for the systematic construction of new disease agents. The announcement of the artificial replication of a virus DNA last December was followed by some rather premature talk about the moral problems of replicating, and altering human DNA. We have a much more immediate concern for the moral problems of the engineering of virus DNA for military purposes.

These anxieties have provoked considerable bitterness in the scientific community and even demonstrations pointlessly misdirected at the Army's biological research laboratories at Ft. Detrick, Md. In recent years, this installation has concentrated on the technology of handling dangerous, infectious materials for research purposes. Its experience is quite valuable for public health work and has been openly published.

Nevertheless, even these positive contributions have a seamier side. The hazards of dealing with dangerous viruses is one of the few discouragements to keep a smaller country from starting its own BW program. As we develop and publicize this technology, we make easier the proliferation of the darkest arts throughout the world.

The makers of policy in Washington, not the technicians at Ft. Detrick, are the just targets of criticism. And they should be chastised less for any malevolent motives in this field than for mere inertia, for technical unfamiliarity, for blind