The panic raised by Carson’s book spread far beyond American borders. Responding to its warning, the governments of a number of developing countries called a halt to their DDT-based anti-malaria programs. The results were catastrophic. In Ceylon, for example, where, as noted, DDT use had cut malaria cases from millions per year in the 1940s down to just 17 by 1963, its banning in 1964 led to a resurgence of half a million victims per year by 1969. In many other countries, the effects were even worse.
Attempting to head off a hysteria-induced global health disaster, in 1970 the National Academy of Sciences issued a report praising the beleaguered pesticide:
To only a few chemicals does man owe as great a debt as to DDT. It has contributed to the great increase in agricultural productivity, while sparing countless humanity from a host of diseases, most notably, perhaps, scrub typhus and malaria. Indeed, it is estimated that, in little more than two decades, DDT has prevented 500 million deaths due to malaria that would otherwise have been inevitable. Abandonment of this valuable insecticide should be undertaken only at such time and in such places as it is evident that the prospective gain to humanity exceeds the consequent losses. At this writing, all available substitutes for DDT are both more expensive per crop-year and decidedly more hazardous.
To some, however, five hundred million human lives were irrelevant. Disregarding the NAS findings, environmentalists continued to demand that DDT be banned. Responding to their pressure, in 1971 the newly-formed Environmental Protection Agency (EPA) launched an investigation of the pesticide. Lasting seven months, the investigative hearings led by Judge Edmund Sweeney gathered testimony from 125 expert witnesses with 365 exhibits. The conclusion of the inquest, however, was exactly the opposite of what the environmentalists had hoped for. After assessing all the evidence, Judge Sweeney found: “The uses of DDT under the registration involved here do not have a deleterious effect on freshwater fish, estuarine organisms, wild birds, or other wildlife.... DDT is not a carcinogenic hazard to man.... DDT is not a mutagenic or teratogenic hazard to man.” Accordingly, Judge Sweeney ruled that DDT should remain available for use.
Unfortunately, however, the administrator of the EPA was William D. Ruckelshaus, who reportedly did not attend a single hour of the investigative hearings, and according to his chief of staff, did not even read Judge Sweeney’s report. Instead, he apparently chose to ignore the science: overruling Sweeney, in 1972 Ruckelshaus banned the use of DDT in the United States except under conditions of medical emergencies.