DDT—Before Silent Spring

DDT—BEFORE SILENT SPRING

An Extraordinary Insecticide

In early June 1944 war-time censorship was lifted from one of the great scientific discoveries of World War II. "DDT will be to preventive medicine what Lister's discovery of antiseptics was to surgery," said Lt. Col. A. L. Ahnfeldt of the U.S. surgeon general's office. DDT stopped a typhus epidemic in Naples and promised to wipe out mosquitos and malaria; to eradicate the household fly, cockroach, and bedbug; and to control some of the most damaging insects that prey on the world's crops.

Amazing Properties

DDT (dichlorodiphenyltrichloroethane) was first synthesized in 1874 from chlorine, alcohol, and sulfuric acid. Its insecticidal powers were discovered in the middle 1930s. It remained active for weeks or even months, and it eliminated the need for repeated respraying. In 1944 the use of DDT as a delousing agent was publicly known for several months, when the army and the manufacturers of the insecticide joined in announcing some of its other amazing properties:

• Sprayed on a wall, it killed any fly that touched the wall, for as long as three months.
• A bed sprayed with DDT remained deadly to bedbugs for three hundred days.
• Clothing dusted with it was safe from typhus-bearing lice for a month, even after eight launderings.
• A few ounces dropped in a swamp killed all mosquito larvae.
• It was deadly to such common household pests as moths, roaches, termites, and fleas.
• As a crop protector, it was effective against potato beetles, cabbage worms, apple-codling moths, Japanese beetles, aphids, fruit worms, and even corn borers.

Control of Typhus. Effective control of typhus required eliminating lice as a carrier of the disease. During World War II DDT was made up into a powder known as AL63, used to spray soldiers' clothing at regular intervals. The insecticide impregnated all underclothing to provide individual protection against typhus. So great was DDT's potential that seven U.S. laboratories and hundreds of biochemists concentrated on refining it. Manufacturers turned out about 350,000 pounds a month—all for the army. The pure chemical itself had little effect; it was good only in an oil solution or when mixed with an inert powder. According to scientists, concentrated DDT was toxic to men and animals when swallowed, but in the weak dilutions used for sprays and dusts, "it has been found harmless to the skin." When the war ended other uses for the chemical were quickly found, especially in the agricultural industry. In the 1940s the public looked at DDT as a great scientific gift. But with the publication of marine biologist Rachel Carson's 1962 study, Silent Springy the public and the scientific community became alarmed by DDT's devastating effects on the natural environment, and use of the chemical within the United States was gradually curtailed.

DISCRIMINATION IN MEDICAL SCHOOLS

The proportion of "minority-group" students admitted to medical schools in a normal prewar year (1940) varied widely depending on the school:

	Percent admitted:
School	Catholics	Italians	Blacks	Jews
Yale University	14	4	4	12
Tufts College Medical School	50	10	0	15
University of Illinois	20	5	1.5	41.8
University of Rochester	13	2	0.6	6
Bowman Gray School of Medicine of Wake Forest College	1.5	0	0	1.5
Hahnemann Medical College	31	9	0	9
Case Western Reserve University	21	8	1	15.5
Creighton University	54	18	0	4
University of Buffalo	36.97	10.9	0	10.9
Women's Medical College of Pennsylvania	15	3	0.9	31
Syracuse University College of Medicine	17.8	4.5	0	12.7
Queens University at Kingston	13.67	2.16	0	5.4
Georgetown University School of Medicine	85	19	0	8
Boston University	50	15	0.3	20
University of Virginia	3	1	0	10

Source:

Frank ingdon, "Discrimination in Medical Colleges," American Mercury (October 1945): 397.

Sources:

"DDT," Time (12 June 1944): 66+;

Roderick E. McGrew, Encyclopedia of Medical History (New York: McGraw-Hill, 1985), pp. 171-172, 351.