TEXT ON SCREEN: April 3, 1963

ARCHIVAL (CBS REPORTS, THE SILENT SPRING OF RACHEL CARSON, 4-3-63):ANNOUNCER: This is one of the nations bestsellers. Up to now, 500,000 copies have been sold, and Silent Spring has been called the most controversial book of the year.

NARRATION: Rachel Carsons push to limit the use of powerful pesticides like DDT helped spark the American environmental movement.

ARCHIVAL (CBS, 8-12-00):VICE PRESIDENT AL GORE: Rachel Carson is one of those rare individuals who brought about change in all of our lives.

NARRATION: But the seeming loss of this pesticide in the fight against malaria also turned her into a poster child for environmental regulation gone too far.

ARCHIVAL (CSPAN, 6-9-09):REPRESENTATIVE DANA ROHRABACHER (R CALIFORNIA): DDT was eliminated and malaria made a comeback and millions of children in third world have died because of this nonsense.

ARCHIVAL (FOX BUSINESS, 7-11-15):JOHN STOSSEL: Although environmentalists worship her, I say shes a mass murderer.

MARK H. LYTLE (AUTHOR, THE GENTLE SUBVERSIVE): If you discredit Rachel Carson, you discredit the founding principle of the EPA. The idea that Carson gave DDT such a bad name that it was banned in much of the world is a gross oversimplification.

NARRATION: As the world continues its fight against malaria, what lesson does Silent Spring hold?


MARK H. LYTLE: She was a very soft-spoken soul who loved nothing better than going down to the tide pools of the rocky Atlantic shores and studying creatures in their habitats and their relationship to each other.

NARRATION: The naturalist and science writer Rachel Carson spent decades urging Americans to see the beauty around them. But in 1962, Carson published Silent Spring, and her message took on markedly different tone.

ARCHIVAL (CBS REPORTS, THE SILENT SPRING OF RACHEL CARSON, 4-3-63):RACHEL CARSON: Man is part of nature, and his war against nature is inevitably a war against himself.

NARRATION: To Carson, that war was exemplified by the growing use of DDT a potent synthetic insecticide that was so revered for its ability to kill malaria-carrying mosquitoes during World War II, that its discovery led to a Nobel Prize.

ARCHIVAL (DOOMSDAY FOR PESTS, 1946):ANNOUNCER: This diabolic weapon of modern science saved millions of humans but killed billions of insects. Men with this newly discovered force has at long last gained the upper hand in our age old struggle.

NARRATION: DDT was soon billed as the solution to every insect pest. And, in time, upwards of 80 million pounds was being sprayed annually in the U.S. alone applied to everything from vast forests and cropland to spreading tracts of suburban American homes.

RAYMOND JOHN ST. LEGER (ENTOMOLOGIST, UNIVERSITY OF MARYLAND): This was the advent of better living through chemistry, and DDT was the wonder child.

ARCHIVAL(DOOMSDAY FOR PESTS, 1946):ANNOUNCER: Once a bug comes into contact with DDT he is lost. The effect is disastrous.

RAYMOND JOHN ST. LEGER: Basically like a chemical holocaust against these insects, it drove lots of insect populations down. And it was enormously effective.

NARRATION: But Carsons research showed the massive spraying of DDT and other insecticides was causing a hidden harm.

MARK H. LYTLE: Carson forced us to consider an invisible threat, something that we might not smell, you might not see; but which had all kinds of unintended consequences.

ARCHIVAL (CBS REPORTS, THE SILENT SPRING OF RACHEL CARSON, 4-3-63):RACHEL CARSON: We poison the caddis flies in a stream, and the salmon runs dwindle and die. We poison the gnats in a lake, and the poison travels from link to link of the food chain. We spray our elms, and the following springs are silent of robin song.

MARK H. LYTLE: She alerted us to the possibility that, in trying to improve on nature, we were actually poisoning ourselves. But to have a woman question the authority of science, and then of scientific men was something that created a great deal of discomfort in some quarters and downright hostility in others.

ARCHIVAL (CBS REPORTS, THE SILENT SPRING OF RACHEL CARSON, 4-3-63):ERIC SEVAREID: Time magazine called Miss Carsons book an emotional and inaccurate outburst.

ARCHIVAL (CBS REPORTS, THE SILENT SPRING OF RACHEL CARSON, 4-3-63):DR. WHITE-STEVENS: The major claims in Ms. Rachel Carsons book, Silent Spring, are gross distortions of the actual facts. If man were to faithfully follow the teachings of Miss Carson, we would return to the Dark Ages, and the insects and diseases and vermin would once again inherit the earth.

NARRATION: But, as evidence mounted that DDT was a persistent and damaging environmental toxin, its pervasive spraying raised increasing political and scientific alarm.

ARCHIVAL (CBS NEWS, EVENING NEWS, 12-23-69):WALTER CRONKITE: A government-backed scientific panel today reported that pesticides may, indeed, represent a grave threat to mankind.

ARCHIVAL (CBS NEWS, EVENING NEWS, 11-12-69):ERIC SEVAREID: The average American already has more DDT in his body than is permitted in the meat and fish that we eat. It does not go away. It accumulates, and it passes to babies through their mothers milk.

NARRATION: By the 1970s, Carson was being hailed as an environmental hero, while DDT was in retreat with a host of developed countries, including the US, severely limiting its use.

MARK H. LYTLE: Silent Spring forced us to reconsider a fundamental faith in science and technology.

NARRATION: But, as the decades passed, the disaster some critics had predicted seemed only too near.

ARCHIVAL (ABC NEWS, 7-19-00):PETER JENNINGS: In Africa and Asia, the mosquito is a mass killer. More than 2 million people die every year from malaria, which mosquitoes transmit.

ARCHIVAL (CNN, 4-13-07):JOHN ROBERTS: The Centers for Disease Control estimates that a child in Africa dies from malaria every 30 seconds.

NARRATION: And the critics knew just whom to blame.

ARCHIVAL (FOX NEWS, 9-2-09):GLENN BECK: By the 1960s DDT had all but eradicated malaria then came Rachel Carlsons silent spring book.

ARCHIVAL (FOX BUSINESS, 7-11-15):JOHN STOSSEL: Her misleading bestseller got the pesticide DDT banned.

ARCHIVAL (FOX NEWS, 9-2-09):GLENN BECK: But the progressive nut balls had it wrong, as usual.

ARCHIVAL (CSPAN, 6-9-09):REPRESENTATIVE DANA ROHRABACHER (R CALIFORNIA): And what is the result of DDT being banned? Malaria out of control in third world countries where before it had been nearly eliminated.

NARRATION: But places like Burkina Faso tell a different story. Even though DDT was never banned in the fight against insect-born disease here, the tiny country has become an epicenter of the worlds malaria epidemic.

ZONGO SOUMAILA: When I woke up this morning, I touched him and noticed that my son had a fever. My son is not the only one. All around the village, children are suffering from malaria.

NARRATION: During the rainy season, health clinics like this one in the village of Soumoussou are packed with patients suffering from malaria. Nearly 40 percent of the countrys residents end up contracting the disease every year.

ABDOULAYE DIABATE (ENTOMOLOGIST, RESEARCH INSTITUTE OF HEALTH SCIENCES, BURKINA FASO): Go to any single healthcare. You will see for yourself. You will see a lot of people with kids there I mean just laying down on the floor, suffering and then waiting for the treatment.

NARRATION: The problem is that the mosquitoes here have become resistant to the pesticides used against them, including DDT.

RAYMOND JOHN ST. LEGER: Insects are very good at out-evolving constraints, and so all over the world lots of different insect species developed resistance against DDT.

NARRATION: Mosquitoes that had a genetic propensity to metabolize DDT survived the spraying, and every year, those survivors reproduced and multiplied.

In many African countries, that resistance combined with decades of government neglect, poor infrastructure and abysmal health care systems to turn malaria into a perfect storm.

ABDOULAYE DIABATE: In West Africa you cant really use DDT, because resistance is extremely high pretty much everywhere.

RAYMOND JOHN ST. LEGER: DDT didnt work. Which is nothing to do with Silent Spring.

NARRATION: In fact, Carson had warned of this very problem.

ARCHIVAL (CBS REPORTS, THE SILENT SPRING OF RACHEL CARSON, 4-3-63):RACHEL CARSON: Inevitably, it follows that intensive spraying with powerful chemicals only makes worse the the problem it is designed to solve.

RAYMOND JOHN ST. LEGER: Rely on a single insecticide, youll get immune insects.

NARRATION: Over the last decade, malaria rates have come down through a combination of new anti-malarial drugs and insecticide treated bed nets. But these results are endangered by the same mistakes over-reliance on a small set of tools, including pyrethroid insecticides.

RAYMOND JOHN ST. LEGER: It used to be that you could kill a mosquito with pyrethroid insecticide in minutes. Now, ten hours of exposure kills about 25 percent of them. Unless we get new technologies to box in the mosquito very quickly, then were probably gonna lose all the gains weve got from the last ten years.

NARRATION: Thats because the mosquito continues to adapt evolving not only new defenses to insecticides, but new feeding habits as well.

RAYMOND JOHN ST. LEGER: Some mosquito populations can actually recognize the silhouette of a door, and they go for people when they come in and out of doorways. Thats how sophisticated evolution can be in changing the behavior.

NARRATION: Here, in this cluster of research sites set among Burkina Fasos rice fields and villages, promising new strategies are put through their paces including one developed in Raymond St. Legers Maryland lab.

RAYMOND JOHN ST. LEGER: Most insects dont die of old age, or because they get snapped up by a passing bird. They actually get killed by disease. And more insects die from fungal disease than any other kind of disease agent.

NARRATION: St. Leger decided this fungus could be improved upon, so he genetically altered it to produce a spider venom, turning the fungi into a mosquito terminator of sorts.

RAYMOND JOHN ST. LEGER: So, basically its a vehicle which makes its own insecticide and then functions like a hypodermic. The fungus injects the insecticide straight into the blood of the insect.

NARRATION: Since mosquitoes must first be infected by the malaria parasite before they can pass it onto humans, Johns Hopkins University immunologist George Dimopoulos has genetically supercharged the the mosquitos natural defenses against contracting the disease.

He has also used bacteria found in mosquitoes intestines to help block the development of the parasite before it can multiply.

GEORGE DEMOPOULOS (DEPUTY DIRECTOR, JOHN HOPKINS MALARIA RESEARCH INSTITUTE): Its like giving the mosquito a probiotic that protects them against malaria.

RAYMOND JOHN ST. LEGER: So, you can put all of these different, innovative approaches together. They all dovetail with each other, and thats gonna be the solution. The solution isnt gonna be relying on any single technology as the silver bullet.

NARRATION: These scientists stress the need for a more holistic view of pest control, which is exactly what Rachel Carson was advocating for in Silent Spring. Despite claims by some modern-day critics, Carson understood there was still a need for pesticides.

ARCHIVAL (CBS REPORTS, THE SILENT SPRING OF RACHEL CARSON, 4-3-63):RACHEL CARSON: We must go on to think in terms of other methods of control, of much more scientific, much more accurate and precise methods. You cant just step in with some brute force and change one thing without changing a good many others.

RAYMOND JOHN ST. LEGER: We are learning that lesson. Were doing our best to learn that lesson.

NARRATION: The mosquito, meanwhile, continues to evolve, an ever-adaptable animal carrying not just malaria, but Dengue, Yellow Fever, Zika, and a host of other diseases as it pursues its ancient hunt for human prey.

RAYMOND JOHN ST. LEGER: A recent study estimated that vector-borne diseases mostly mosquito-borne diseases have killed half of all the humans whove ever lived. They are by far and away the most dangerous animal. Theyre even more dangerous to us than other people are. So, ideally, we want to develop an evolution-proof system for controlling them.