The Pesticide Problem
Detectable pesticide residues are present in about 40% of all foods analyzed as part of an ongoing government study--although the amounts being found are minuscule, according to a recent federal survey.
The U.S. Food and Drug Administration’s Residue Monitoring program reported that its laboratory results for 1991 “indicate that the levels of pesticide residues in the U.S. (food supply) are generally below established safety limits.” Critics of the study argue that the FDA’s findings are too fragmentary to substantiate any such sweeping claims.
Interpretation of the government’s data is at the heart of the issue. The FDA frequently states that its testing shows that as much as 99.2% of the food analyzed contains either zero residues or amounts considered legal. Environmentalists and consumer groups say that at least half of the samples tested contain at least some pesticides and that the figure is probably higher because the FDA’s program is riddled with statistical “weaknesses.”
The bulk of the FDA pesticide testing uses the Multiresidue Method, a laboratory procedure that can detect only about half of the 300 chemicals that may be legally used on food. The remaining 150 chemicals are the focus of less than one in 10 FDA laboratory pesticide analyses.
“There are hundreds of commodities out there and FDA is obligated to cover all of them to some extent,” said John Jones, FDA program manager for pesticides and chemical contaminants in Washington. “We could (test for) all 300 farm chemicals but the cost would be prohibitive.”
This disparity in its coverage prompted FDA, in its 1991 report, to concede that the small number of samples taken of some commodities may be insufficient to determine their overall safety. An FDA official did not specify which foods fell into this category.
“One of the fundamental flaws in their program is that FDA usually tests for only half of the chemicals that may be in the food,” says Lawrie Mott, senior scientist for the Natural Resources Defense Council in San Francisco. “And what’s a major concern is that some of the pesticides that they are missing are the really hazardous ones . . . These shortcomings should lower consumer confidence in FDA results.”
But Jones says FDA has conducted lab tests on 19,082 domestic and imported food samples in 1991 and about 200,000 samples over the past 10 years. “There have not been high violations rates for any given commodity during that time,” he said.
Five major groups of domestic and imported food were tested by the agency: grains; milk and dairy products; fish and shellfish; fruits, and vegetables. Also examined were a miscellaneous lot including items such as vegetable oils, nuts and baby food, which did not fall in the principal categories. (Meat and poultry, which are regulated by the U.S. Department of Agriculture, were not included in this study.)
About 35% of the 8,291 domestically produced foods contained legal pesticide residues; 64% had no detectable residues; 0.8% were in violation. By comparison, 29% of the 9,933 samples of imported food contained legal chemical levels; 69% were residue-free; 2.3% were violative.
The violation rate for the imports was three times the level for domestic products. As a result, FDA “continues to emphasize testing of imported food shipments,” the report stated. (Violations can take two forms: residues in excess of the level allowed by law or illegal use of a chemical not approved for application on a particular crop.)
Another aspect of the FDA residue monitoring program is its compliance feature: Agency officials target those commodities with previous histories of violations or where pesticide misuse is suspected. Under the compliance sampling program, 19% of the domestic foodstuffs, all fruits, were considered violative. The imports, which included fruit, vegetables, fish and grains, had an 11% violation rate.
“If you look at (the testing program) over time then you can draw (positive) conclusions (about food safety),” says the FDA’s Jones.
Despite pressure by environmentalists, consumers and food processors to encourage agriculture to decrease the amount of farm chemicals applied to crops and soil, residue levels have remained relatively steady during the last five years of the FDA testing program. Between 35% and 42% of the domestically tested product contained some type of residue during that time span.
A produce industry trade group representative was surprised to learn of the relatively stable residue level.
“In general, (the levels) should have declined because the growers are less dependent on pesticides today and are using alternative methods such as Integrated Pest Management techniques,” says Valerie Jewitt, regulatory affairs director for the United Fresh Fruit and Vegetable Assn. in Alexandria, Va. “Often, when we talk with growers, they report using less than the maximum amount of a chemical recommended on a product’s label. So, the residues we’re finding are (well below) the levels allowed.”
“In general, (the levels) should have declined because the growers are less dependent on pesticides today and are using alternative methods such as Integrated Pest Management techniques,” says Valerie Jewitt, regulatory affairs director for the United Fresh Fruit and Vegetable Assn. in Alexandria, Va. “Often, when we talk with growers, they report using less than the maximum amount of a chemical recommended on a product’s label. So, the residues we’re finding are (well below) the levels allowed.”
“In general, (the levels) should have declined because the growers are less dependent on pesticides today and are using alternative methods such as Integrated Pest Management techniques,” says Valerie Jewitt, regulatory affairs director for the United Fresh Fruit and Vegetable Assn. in Alexandria, Va. “Often, when we talk with growers, they report using less than the maximum amount of a chemical recommended on a product’s label. So, the residues we’re finding are (well below) the levels allowed.”
The agency did find that some chemicals are particularly resilient. DDT--a reproductive toxin and carcinogen banned from use in this country in 1972--was found in 63% of the 188 samples of fish and shellfish analyzed by FDA. The levels detected, however, were below 5 parts per million, the point at which the food would be considered contaminated.
DDT was also the third most frequently detected chemical in a portion of the FDA program called the Total Diet Study, which measures pesticide residues in foods that have been washed, prepared and cooked. DDT was found in 10% of the prepared foods analyzed in the Total Diet Study. Only malathion and chlorpyrifos-methyl were present in greater amounts.
The DDT findings “point out the incredible persistence of DDT, and we continue to pay the price for government inaction on this compound,” says NRDC’s Mott. “DDT is also a perfect example of why government officials need to think long and hard about letting new chemicals on the market.”
Ellis Gunderson, an FDA chemist, disagreed.
“(The DDT findings) are not a surprise,” he said. “These are extremely low levels and the difference between current-day DDT findings and the past is that the levels now being detected have dropped dramatically. And so has (estimated) public dietary intake.”
The FDA’s 1991 Residue Monitoring report did not address environmentalists’ concerns that the residue levels allowed in food by U.S. law are too high for some segments of the population, particularly children.
