For whatever reason, this past week was a scary week for the media regarding food. One piece of news came from Consumer Reports regarding aspartame, yet again, as well as a story from Newsweek and other outlets regarding the purported dangers of pesticides on apples. It has become very difficult to keep pace with all the junk-science and fake news in the media.
On Oct. 25, 2017, Newsweek ran this terrifying headline: "Your Fruit Is Covered With Nasty Pesticides: Scientists Have Discovered the Best Way to Wash Them Off." The Newsweek article was based upon a report published in the Journal of Agricultural and Food Chemistry, which had provided the results of washing pesticide residue off apples using three different methods. These methods were Clorox bleach, baking soda and tap water. The researchers, from the University of Massachusetts, stated, "Removal of pesticide residues from fresh produce is important to reduce pesticide residue exposure to humans," and concluded that washing apples with baking soda was the most effective of the three methods. However, here is the rub (excuse the pun).
The researchers applied the maximum legal limit of pesticides onto the apples, which would be expected, but only waited 24 hours prior to washing and measuring for residue samples after cleaning with all three methods. In real life, the EPA does not allow any harvesting of apples after spraying for seven days, not 24 hours, and 14 days if it is a pick-yourself orchard. This allows considerable time for any pesticide applied to degrade by normal environmental conditions and reach well-established safe levels of exposure.
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As an example, for thiabendazole, the fungicide used in this study, which is used to prevent mold growth during the storage of apples, legal tolerance is set at 5 parts per million (ppm). Here are some examples from the American Council on Science and Health as to what 1ppm looks like in real-world terms:
- 1 gram of residue in 1,000,000 grams (2,200 lbs.) of food;
- 1 inch in 16 miles;
- 1 minute in 2 years;
- 1 cent in $10,000;
- 1 pancake in a stack 4 miles high.
So, the legal 5 ppm is equivalent to 5 grams of residue in 2,200 pounds of apples. However, even this insignificant level is not what consumers are exposed to. Steve Savage, who holds a Ph.D. in Plant Physiology from UC Davis and runs the website Applied Mythology, pointed out in an email that "the 2014 USDA data shows that the residues found are all below the 5 ppm tolerance." He forwarded this data, and this is what I found. Eighty-eight percent of the samples detected are far less than 1 ppm of residue, or less than 1 gram of residue for every 2,200 pounds of apples. Twelve percent of samples detected only 1-2 ppm, or, 1-2 grams for every 2,200 pounds of apples. This is an incredibly insignificant amount. But just how insignificant, and what does it mean in real-life terms?
There is a term used for pesticide safety called NOAEL, which stands for No Observable Adverse Effect Level. In toxicology this means the highest tested dose or concentration of a substance at which no adverse effect is found. Using the highest reported residues to illustrate how safe this exposure level is, women could consume 850 apples per day without any effect, even if the apples had the highest residue of pesticide allowed by the USDA. Men could consume 1,190, and children could consume 340. This information is provided by SafeFruitsandVeggies.com. Not so scary, is it? That is a lot of apple pie.
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Thiabendazole is referred to as a systemic pesticide, which means it is absorbed into the tissue of the produce it is applied to – and it is supposed to. This is how it prevents the fungal growth during storage and allows consumers who do not have an orchard in their backyard, or close by, to have access to and enjoy apples. As Dr. Savage points out, "Without these fungicides applied on the way into storage, there would be much more food waste. Therefore, one would expect to find residues." So, the obvious point here is the standard risk-to-benefit ratio with the use of thiabendazole. I would argue that it is quite clear that considering the non-existent health risk for its use compared to the health benefits, the storage and shipping of apples to millions of people, we need to be thankful for the product's development. Additionally, it is rapidly excreted in the urine and feces. It does not bioaccumulate in body tissue.
The other pesticide used was phosmet, which is used to help control for apple maggots, something no one wants in their apple when they bite into it. It does not penetrate the produce flesh, and the EPA mandates a waiting period of 7 days post-application before apples can be harvested, not 24 hours as used in this study. The EPA has set a tolerance level of 10 ppm, which is 10 grams per 2,200 pounds of apples. However, as with all pesticides, this is not what the consumer is exposed to, if any. The 2014 USDA sampling data demonstrate detection levels of 0.005 ppm to 0.280 ppm. Again, these are incredibly low numbers, almost a non-existent detection level. Most samplings were below the 0.076 ppm levels, and this would be prior to the consumer rinsing them off with water at home.
Now considering the facts and a little more detailed evaluation of your actual exposure to pesticides, do you consider the Newsweek headline, "Your Fruit Is Covered With Nasty Pesticides," fake news or real news?
Enjoy your apple pie on Thanksgiving, and be thankful for the lack of mold and maggots in the apples you used to make it with. Pesticides are a blessing to us, enabling us to produce food for millions of people, especially the poor.