417 



negligible. The PSAC report on pesticides, also in 1963, cited an in- 

 vestigation into the toxicity of DDT in which a small group of volun- 

 teers had ingested "up to -35 mg. of DDT per day o\'er a period of 

 months'- and yet was "reported to show no apparent ill effects during 

 18 months of gross observation." However, the PSAC report warned 

 that "possible long-term effects*' could not be predicted for DDT "on 

 the basis of the limited clinical studies available." ^' 



Although no short-term toxicity had apparently been manifested by 

 DDT as applied to humans, and the effects of long-term exposure were 

 controversial, there were many other pesticides on the market, some of 

 which were indubitably toxic. An early warning was expressed in 1948, 

 by the Council on Foods and Nutrition of the American Medical Asso- 

 ciation. It took note of the rapid increase in new, potent pesticides 

 which posed indeterminate hazard to man. An editorial accompanying 

 the warning spoke of the "phenomenal" introduction of "several thou- 

 sand" brands of new insecticides, fungicides, and herbicides, intro- 

 duced on the market, mostly since DDT. "Little is known about either 

 the acute or chronic pathologic effects on man of these new insecti- 

 cides." The editorial observed that "when pesticides are poisonous 

 to insects they are usually poisonous to man.'* It noted that some of the 

 new poisons were "* * * incor]3orated in the plant tissues and cannot be 

 removed." These were "particularly insidious." The editorial urged 

 "prompt voluntary action by the industry" and, if necessary, "suitable 

 legislation must be considered and effective means of [Government] 

 control promptly established." Moreover : 



Important is the detection of i)esticicle residues by practical methods in fresh 

 as well as in processed foods. The metabolism of insecticide residues and their 

 acute and pathologic effects on mammals must also be determined. 



The editorial warned that — 



Even though added controls may impede the development of pesticides, these 

 are essential precautions which must be taken in order to avoid the danger of 

 mass poisoning, which might well offset the jwtential benefits of the new agents." 



Appearance of '•^Silent Spinng^'' ; wide impact of its message 



Late in 1962, the book by Rachel Carson appeared. More than a dec- 

 ade had elapsed since the appearance of the Osbom warning and the 

 AMA statement. The message of the Carson book was simple and clear : 

 In his conquest of pests, man's indiscriminate use of potent chemicals 

 had already done great — perhaps irreparable — damage ; it was threat- 

 ening himself and destroying his environment. Backed by 55 pages of 

 footnotes Miss Carson declared that, in substance- — 



Some pesticides had proved fatal to man after the slightest con- 

 tact (p. 30).^ 



Food chains (e.g., grain to hens to eggs; hay to cows to milk) 

 sometimes concentrated stable insecticides to dangerous extents 

 (p. 22). _ 



Some insecticides were 40 to 50 times as toxic as DDT for bird 

 life (p. 25). 



The most toxic insecticides of all — the organophosphates — were 

 being sprayed in huge quantities from airplanes and motorized 

 blowers to control agricultural pests over large acreages (p. 30). 



^ Reproduced In Hearings • * • Ibid., p. 45. 



» JAMA (Aug. 28, 1948, vol. 137, No. 18), pp. 1604-1605. 



89-044—69 28 



