Are the chemical pesticides used by American farmers, at an annual cost of $4 billion, unsafe at any level -- or vital to feeding a hungry world? Given added visibility following California's battle over pesticide spraying to eradicate the Mediterranean fruit fly, some environmental groups are renewing demands for sharply reducing or even ending pesticide use. They hope public protests in California will lead Congress to tighten pesticide restrictions. House hearings begin July 16 on federal pesticide policies.
Yet if the United States stopped the use of pesticides, crop production could drop 10 percent, according to Us Department of Agriculture estimates, or 30 percent, according to the National Agricultural Chemicals Association (NACA). Even a 10 percent cut in crop yields would be intolerable, say NACA spokesmen, at a time when the world is growing increasingly dependent on US food exports.
For NACA's 115 member companies, the answer to feeding the world better is raising pesticide use to US levels on the 87 percent of the world's potential cropland, which lies outside the United States. That switch would turn the current $6 billion overseas market for crop protection chemicals into one worth more than $26 billion a year. Such an investment would pay high dividends, the chemical industry argues, for developing countries in need of higher yields to feed swelling populations.
A variety of environmental groups reject the rosy picture painted by pesticide manufacturers. Meanwhile, the US Department of Agriculture (USDA) draws fire from both sides by pursuing a middle course and concentrating research efforts on "integrated pest management" programs, or IPM. These combines minimal use of chemical pesticides with natural controls such as introducing predators or developing pest-resistant plants.
USDA approach has support from the congressional Office of Technology Assessment, which reported in 1979 that IPM could reduce pesticide use up to 75 percent for some crops, reduce preharvest pest-caused losses by 50 percent, and reduce overall pest control costs significantly.
"The Pesticide Conspiracy," by the late Robert van den Bosch, an entomology professor at the university of California at Berkeley, goes further. It concludes that industry pressures have put America on an "insecticide treadmill." The book credits chemical overkill with creating new strains of pesticide-resistant weeds, insects, and parasites that demand ever-increasing use of chemical controls.
Sharp disagreements over pesticide effectiveness are not new. But new attention is being paid to experts on both sides of the pesticide fence due to California's battle over spraying the pesticide, malathion, to control a Mediterranean fruit fly or Medfly infestation.
Williams Hollis, NACA science coordinator, points our that state and federal officials spent $23 million over the past year using the latest IPM techniques to combat the Medfly problem "and obviously it hasn't worked." He says this infestation poses a tremendous threat, because instead of simply reducing yields , it could wipe out entire crops.
Dr. Hollis stresses that in its support for pesticides, NACA rejects "any relaxation in regulations for safety and environmental protection." Such government protection for both producers and consumers, he says, "is something we feel is absolutely essential."
The pesticide industry and the government share of same priorities, says hollis: "providing safe, wholesome food at a reasonable cost. "He says that industry and government cooperate fully in rigorously testing all chemicals used in food production.
Hollis hopes that as a result of Californians' "unfounded fears" about pesticide spraying to control the Medley, "people are going to learn more about the extensive scientific research that's gone into each product."
Robin Wagner, a pesticides research worker for the National Association of Farmworker Organizations, shares the concerns of many Californians over potential human health risks posed by malathion spraying. But, as with most experts in this field, she balances the overall costs against overall benefits for society. She concludes that it is better to control the Medfly with relatively small does of malathion now rather than risk having to use larger amounts of more toxic chemicals later.
Congressmen, the US Environmental Protection Agency, and the USDA take a similar view: that any pesticide is a potential hazard but that the greatest need now is to control the Medfly before its spread endangers not only California produce but crops in other states, too. Any spread, officials warn, would threaten farmers, drive up consumer prices, and reduce important export sales.
Jay Feldman, the Consumer Coalition for Heatlh's pesticide expert, joins NACA officials in hoping that the California Medfly problem will increase awareness of an important issue. He believes that the public will "realize that there is wide disparity in the scientific community about pesticide use and realize that the burden is on the public to prove there is a health problem rather than on the chemical companies."
The government, says Mr. Feldman, should increase support for "alternate control strategies based on nonchemical or reduced- chemical approaches."
Feldman accepts that it is too late for California to avoid pesticide spraying to control the Medfly. The problem, he says, is that "without a long-run strategy, we put ourselves in a situation where we see explosions, such as with the Medfly or the gypsy moth, which have to be controlled with chemicals." Such explosions, he insists, can be avoided in the future if the country learns fro m the Medfly experience and sets up a long-term IPM program.