Aphidius wasp attacking aphid that could otherwise damage the crop.
Aphidius wasp attacking aphid that could otherwise damage the crop. Biological solutions may be the best replacement for hazardous chemicals. Photo by David Jansen, Bio-Bee Ltd.
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Next month marks 50 years since the publication of Rachel Carson's Silent Spring, the book widely credited with helping to launch the environmental movement. The approach of that momentous golden anniversary is a good impetus to look at what has been accomplished since Carson forced the world to take a close look at what it was doing to the living creatures in its midst.

An ecologist and writer, Carson was the first to publicly expose the detrimental effects of pesticides on the environment, particularly on birds, as well as the hazards they posed to human health. The book ultimately led to the passage of U.S. legislation limiting the use of toxins, and to a ban on DDT in 1972 in the United States.

Carson, born in 1907, began her career as a marine biologist with the U.S. Bureau of Fisheries (later to become the Fish and Wildlife Service ). Her book, "The Sea Around Us," was published to wide acclaim, and gave her a name as a conservationist. She began to be concerned about the effects of synthetic pesticides after a friend wrote a letter to a newspaper describing the death of birds around her property, as a result of the aerial spraying of DDT to kill mosquitoes. Carson decided to write a book on the subject after learning from researchers in different disciplines about the environmental ravages of these chemicals.

In 1962, The New Yorker began to serialize Carson's Silent Spring, the title of which was taken from the Keats poem, "La Belle Dame sans Merci," which contains the line "and no birds sing." The title encapsulated Carson's core message about the devastation being caused by pesticides. Silent Spring, which was published in book form later that year, warned that extensive spraying with certain pesticides was damaging the food chain, and the entire ecosystem. The practice, she warned, would eventually lead to the death of birds from exposure to the toxins.

Carson did not oppose the use of pesticides and insecticides per se, but rather the manner of use, particularly with regard to DDT, which was used extensively in agriculture. Carson argued that pesticides and insecticides were not only harming intended agricultural pests, but were killing beneficial insects and other organisms. She stressed that the chemicals were also exposing human beings to the risk of cancer and other diseases, and that even exposure to minor amounts could cause neurological and genetic damage to people, since some pesticides can be stored in the body.

Pesticides had been seen at the time as a magic solution for eliminating agricultural pests and for eradicating human disease. The use of chemicals in public places was the gold standard. Various authorities assured the public that the pesticides were safe and posed no health risks. No scientist or public official was able to shake this conviction until Carson's authoritative book was published.

The book was groundbreaking not only in its description of the dangers inherent in the use of chemical toxins. It also helped establish the now widely-understood view that every ecosystem is interrelated and that damage to any one component causes damage to all other elements.

Carson explained that long-term use of pesticides was causing insects to develop resistance to the chemicals. "If Darwin were alive today the insect world would delight and astound him with its impressive verification of his theories of survival of the fittest," she wrote. "Under the stress of intensive chemical spraying the weakest members of the insect population are being weeded out. Now, in many areas and among many species only the strong and fit remain to defy our efforts to control them." Attempts to discredit Carson's claims began immediately after publication, and continue today. They are primarily led by the chemical industry, interested in blocking efforts to limit the use of its products. Free market supporters, opposed in principle to increased governmental regulation of chemical products, have also denounced the book. Carson herself had only a brief period of time in which to rebut the attacks on her book. She died of cancer barely two years after its publication, in April 1964.

Even some environmentalists assert that some of Carson's main conclusions were incorrect. Prof. Roger Meiners and Prof. Andrew Morriss, for example, two American environmental policy experts, argue that Carson ignored the fact that pesticides prevented mass starvation and enabled food production to take place on smaller plots, which decreased environmental degradation caused by agricultural production spread over larger areas. They also say she failed to note the fact that populations of several types of birds in the wild actually increased after the introduction of widespread pesticide spraying, and insist she exaggerated when describing the risks of chemical exposure to human health.

But, in fact, more evidence of the dangers of pesticides have been found over the years. Only a few months ago, several studies were published showing a possible link between the drop in the bee population and the use of chemicals.

A biological solution to the bee population problem, to replace a chemical solution, may be found in Israel. Several weeks ago, the Environmental Protection Ministry and the Jerusalem Institute for Israel Studies held a conference that presented environmental innovation technologies, including a biological pest control developed and operated by Bio-Bee Biological Systems, based on Kibbutz Sde Eliyahu.

Company CEO Dr. Shimon Steinberg described how insects grown by the company effectively and efficiently devour the insects that damage agricultural produce. Aphidius wasps attack aphids that damage peppers, for example, and according to Steinberg this has resulted in decreased use of chemicals. In the case of another pest, growers decided to use its biological enemy after they concluded that the pest had developed resistance to the chemicals used against it.