A new report looks at the amount of pesticides that are making their way to our plates. Nutrition Diva examines the results with toxicologist and pesticide expert Dr. Carl Winter.
The FDA recently released its annual Pesticide Residue Report. As pesticides are one of the things people worry most about, I thought we should take a look at what they found. Here to help us make sense of this very technical and complex data is Dr. Carl Winter of the UC Davis. Dr. Winter is a toxicologist who researches the detection of pesticides and naturally-occurring toxins in foods and how to assess their risks. Below are highlights from our conversation. Please click on the audio player to hear the entire interview.
Nutrition Diva: As part of their ongoing pesticide monitoring program, FDA tested 7,000 foods for residues of over 700 different pesticides and selected industrial compounds. Over half of all the samples analyzed contained no pesticide chemical residues at all. 94% of samples were compliant with federal standards. That means that 6% of the samples were NOT compliant. Does that mean that they were unsafe?
Dr. Carl Winter: When higher than expected (or “violative”) residues are found, it doesn’t mean that these foods are unsafe to consume or expose consumers to unsafe levels of chemicals. The vast majority of these violations aren’t due to levels of a pesticide being higher than expected. They usually indicate the presence of trace amounts of a compound that’s been approved, but not for this particular food.
ND: Also, we should point out that these are not random samples. The FDA is purposely testing those foods that they think are most likely to be in violation—because this part of the program is not designed to assess consumer exposure to pesticides. It’s designed to ensure that these chemicals are being used as directed to control the bugs they are intended to control.
CW: Yes, this is sort of like the cop setting up a speed trap. He or she knows exactly where to set up to catch the maximum number of offenders!
ND: This year, the FDA also used some new methods to test foods specifically for glyphosate or Roundup, in response to public concerns about the presence of this chemical in our food supply. What did they find?
CW: As you would expect, they found glyphosate residues on crops that use this product: corn and soy. About a third of the corn and soy had no detectable residues at all. And 100% of the samples were in compliance with regulations.
ND: But can we be confident that these regulations are strict enough to prevent unsafe exposure to this compound?
CW: Before a tolerance level is set, a compound first has to be determined to be safe, even for the most sensitive individuals, based on the maximum concentration that they are likely to be exposed to from all sources, including all foods on which they may be found, drinking water, and household settings. The tolerance is then set to represent the maximum residue anticipated if the pesticide is applied properly. In most cases tolerances could be much higher and still be protective of public health, but they are set lower than that to ensure compliance with proper use protocols. The bottom line here is that violative pesticide residues rarely represent residues of health concern.
ND: In addition to the pesticide monitoring program, the FDA also does something called a Total Diet Study. Foods are selected to represent a typical diet and are prepared the way they would typically be prepared. So foods may be washed, peeled, and/or cooked (or even made into a frozen pizza) before they are analyzed. The idea is to get an idea of how much total chemical residue a consumer is likely to be exposed to from a typical diet.
The TDS included 1,000 foods. Altogether, residues of 155 different pesticides were found, most frequently at trace levels. Of all the residues found in TDS foods, 87 % percent were at levels below 0.01 parts per million (ppm). So, these are very small amounts. But some argue that very small amounts of 155 different things might add up to an unsafe toxic burden. Is that a reasonable concern?