An unsung hero in last week's rehabilitation of the pesticide DDT is Senator Tom Coburn of Oklahoma, a medical doctor and freethinker who makes even fellow Republicans uncomfortable with his habit of speaking unwelcome truths.

Mr. Coburn serves as chairman of the Senate Subcommittee on Federal Financial Management, a perch he used to press international organizations to recommend DDT once again as a way to fight the mosquito-borne diseases that kill millions of people. Last week, the World Health Organization finally put DDT back in its arsenal. "The new WHO position paper on house spraying for malaria control is a revolutionary document," Sen. Coburn applauded. "The junk science and stigma surrounding DDT -- the cheapest and most effective insecticide on the planet -- have finally been jettisoned."

Indeed, a strong argument could be made that no book in recent decades is responsible more death and suffering than Rachel Carson's "The Silent Spring," a screed against DDT for killing birds and other wildlife. Her book, published in 1962, gave birth to modern environmentalism. In 1972, EPA responded by declaring (with little evidence) that DDT is "a potential human carcinogen." As a consequence of such junk science, this invaluable pesticide was banned in most countries around the world. The American Council on Science and Health has called DDT "the single most important pesticide responsible for maintaining human health" in the 1950s and '60s. It was said to be responsible for preventing 500 million deaths due to malaria.

Even the liberal Washington Monthly has noticed that conservative Republicans are the ones carrying the ball on the developing world's malaria crisis. The magazine in July lauded Mr. Coburn and colleagues for "an impressive knowledge of the crisis and the deficiencies" of U.S. bureaucratic efforts. But their work isn't done. While the Sierra Club and Environmental Defense have grudgingly endorsed limited use of DDT, the World Wildlife Fund and others continue to lobby against it. On another front, Mr. Coburn had steadily blasted the U.S. Agency for International Development for spending more money on consultants' salaries in its malaria war than on actually fielding solutions. Ending the DDT ban is a victory for human life, sound science, and compassionate conservatism. Bravo, Dr. Coburn.