All We Are Saying Is Give Peach A Chance

A really ripe peach or nectarine is a fantastic taste experience. Of course the best option is to eat one directly from the tree, but because of two advances, many more people can get a good peach. Scientists in California and Chile have developed a way to “condition” stone fruits so that they can be picked early enough to survive handling and yet still taste nearly as good as they can. They also learned what temperatures to avoid in transit or distribution to keep the quality. Getting good peaches is more possible today than ever, though there is no guarantee depending on how the fruit was handled. So can you enjoy these fruits? Some people don’t think so.

The Environmental Working Group (EWG) publishes a “dirty dozen” list of fruits and vegetables that they claim to have the greatest consumer exposure to pesticides. Their methodology is listed on-line and it intentionally treats all pesticides about the same regardless of their use rate or toxicity. They recommend that consumers either avoid these crops or buy Organic. Are they right?

There is public data available to do a much more careful analysis of this question. For California, the dominant producer of peaches and nectarines, there is a public database of pesticide usage called CALPIP that tells which pesticides are used on which crops and at which rates. There are statistics available about crop production from the California Department of Agriculture. There is data available from various sources on-line about the toxicity of different pesticides (MSDS – material safety data sheets). Gathering this data and processing it takes a significant investment in time, but it leads to a very different picture than what the EWG presents.

On average, each acre of peaches or nectarines got 32 pounds of pesticides in 2008, the latest year with data. That represents 0.66 grams per pound (454 grams) of fruit. Most of that pesticide residue has been broken down before harvest, but that is the upper limit (California EPA does a major survey of pesticide residues on marketed fruit each year and they are very low).

But not all pesticides are equal. 80.2% of all the pesticides used on these crops are scarcely toxic to us at all. Acute toxicity (poisoning potential) is measured by the “LD50” in a rat test expressed as the number of milligrams/kg of body weight it would take to kill 1/2 of the rates in the test. Higher numbers mean low toxicity and this dominant category is less toxic to us than common table salt (LD50 of 3000 mg/kg). Indeed, a great many of these pesticides have LD50 values in excess of 5000 mg/kg.

The next tier of pesticides, 8.9% of the total used, are less toxic than vanillin – the flavor in the vanilla extract in most people’s cupboards. Another 6.7% of the pesticides are less toxic than some of the copper fungicides that are allowed for Organic (yes, pesticides are used on Organic – they are qualified by being “natural,” not because they are the safest options). So, of all the pesticides used on peaches and nectarines, 95.7% are at least as safe as what is allowed on an Organic crop that the EWG recommends.

What about the rest? Another 3% are less toxic than the caffeine that starts many people’s day bringing the total of not terribly scary pesticides to 98.8% of the total.

The final 1.2% of pesticides used on peaches and nectarines includes some materials that are only applied to the ground, not the fruit so the relatively toxic pesticides use represents 0.7% percent of the total. That represents 0.008 grams per pound of fruit without any assumption of breakdown before harvest. To get a toxic dose for a 50 lb child at that rate would require that the child eat 474,000 pounds of fruit in a sitting.

Peach and Nectarine season is coming up. The real data suggest that you should find a retailer that does a good job of getting “conditioned” fruit and storing it well, and then enjoy!

Steve Savage
Steve Savage is a scientist (PhD Plant Pathology) with more than thirty years of diverse experience with crops and agricultural technologies. He has worked on everything from biological controls to chemicals to genetics to biotechnology. He has worked for a university (Colorado State), a large company (Du Pont), a small company (Mycogen) and for the last 13 years as an independent consultant. He writes about farming both to address widespread myths and to confront the real challenges of sustainably feeding a world population headed to 9 billion in an age of climate change. Steve writes from sunny San Diego county in California in an office with a view of his home vineyard and garden. Links to his writing can be found at