By Marvin Pritts, horticulture professor, Cornell University
Each year, the Environmental Working Group (EWG) puts out a list of “dirty” fruits and vegetables that consumers are supposed to avoid because they contain pesticide residues. For the third year in a row, strawberries were number one on the list. The list is misleading, having been created without consideration of several important scientific and social/cultural issues, but its popularity with the press forces growers to struggle with educating customers who have bought into the EWG’s misleading messaging.
Here are some talking points to share with customers to explain why the EWG’s “dirty dozen” list shouldn’t be used to guide their produce selection.
- Data used by the EWG counts the presence/absence of a residue, but does not consider the total amount of residue. This is not a valid method of assessing risk, since the amount of a residue is critical for determining if that residue is toxic.
- Pesticide residues in plants are miniscule and are not know to have any health effects in mammals, whether the mammal is a baby or a sensitive adult. Nearly all fruits and vegetables have levels far below (often a million times lower) levels known to cause physiological effects in humans. Just because a residue exists does not mean it is toxic at such low levels.
- Growers who rotate pesticides to reduce the risk of developing pesticide resistance will score more poorly on the EWG scale than growers who use large amounts of a single pesticide to control a pest.
- Residue data from crops vary greatly depending on where a crop is grown. For example, strawberries grown in the warm, wet climate of Florida receive far more pesticide applications than strawberries grown in the Northeast, yet strawberries are ranked number one for residues, regardless of how and where they are grown. This creates a major disadvantage for local growers.
- Plants produce natural pesticides so they don’t get eaten by pests. The amount of naturally produced pesticides is estimated to exceed human-applied residues by ten-thousandfold. The amount of synthetic pesticide residue is dwarfed by the amount of naturally occurring pest-deterring chemicals already present in plants.
- Plants not treated to manage pests often have higher levels of natural pesticides.
- Human systems have developed mechanisms to detoxify naturally occurring chemicals in the food we eat. These detoxification mechanisms work on both natural and synthetic chemicals, keeping us safe as long as these detoxification mechanisms are not overwhelmed.
- Organically grown food also may contain pesticide residues. Organic growers face the same insect, fungal, and weed pests as conventional growers, so they often will use chemical sprays to manage them. Neither the organic residues nor the synthetic residues have ever been shown to be harmful to humans.
- The health benefits of eating a strawberry—ranked number one on the “dirty dozen” list—far exceed any detriment from consuming a pesticide residue. For example, strawberries have more vitamin C than oranges by weight and are high in antioxidants and nutrients.
- The EWG list discourages consumers from eating healthy fruits and vegetables such as spinach, tomatoes, grapes, and apples, which also rank high on the list and are known to be extremely good for health.
- Consumers already eat far fewer fruits and vegetables than are recommended for good health. This is especially true for low-income populations. The EWG list can do harm to low-income groups by discouraging good eating habits.
- The EWG approach to ranking risk is not supported by any scientific organization, has never undergone peer-review, and has never been published in a scientific journal. Recommendations regarding a person’s ability to reduce pesticide-residue exposure by altering eating habits are not supported by the data
