Every year, the USDA Pesticide Data Program tests for pesticide residues on more than 13,000 samples. These samples of fruits, vegetables, grains, milk, and drinking water, are purchased at grocery stores. In 2004, approximately 76 percent of fresh fruit and vegetables showed detectable pesticide residues; 40 percent of these contained more than one pesticide; and only 0.2 percent exceeded the tolerable levels (Stewart 2007).Pesticide Exposure and Dangers to Children
Children may be more vulnerable to toxins than adults because they are still developing. Organophosphate pesticides, or OG pesticides, have been known to cause neurological damage in children when exposure is too high.
Side effects from OG pesticide exposure include paralysis, seizures, and tremors. The most common sources of OG pesticides are fruits, vegetables, and grains, such as apples, apple juice, bananas, carrots, green beans, oranges, orange juice, peaches, pears, potatoes, winter squash, and tomatoes (Stewart 2007).
To limit pesticide exposure, it’s best to choose organic foods. Studies have shown that organic foods have a higher nutrient content. While nutrient content differs from farmer to farmer, organic varieties do provide significantly greater levels of vitamin C, iron, magnesium, and phosphorus than non-organic varieties of the same food (Crinnion 2010).
Furthermore, with the exception of wheat, oats, and wine, organic foods also provide greater levels of a number of important antioxidant phytochemicals (anthocyanins, flavonoids, and carotenoids).
Pesticides and the Endocrine System
A large number of pesticides (approximately 105) are endocrine disrupting chemicals, or EDC’s, which alter the normal functioning of the endocrine systems of both wildlife and humans.
At the human level, endocrine disruptor pesticides have also been shown to disrupt reproductive and sexual development.
Studies have concluded that pesticide exposure may affect male spermatogenesis, which can lead to male infertility. Furthermore, an increasing number of epidemiological studies link environmental exposure to pesticides and hormone-dependent cancer risks. High levels of pesticides have been found in fat samples from women with breast cancer. The risk of breast cancer may be as many as four times greater in women with increased blood levels of pesticide levels.
A recent study conducted in Spain between 1999-2009 showed that of 2,661 cases of breast cancer reported in the female population, 2,173 (81%) were observed in areas of high pesticide contamination. Similar studies have revealed correlations between damage to the immune system and increased amounts of OG residues in certain cancerous tissues (Mnif et al, 2011).
The Dirty Dozen List
The Environmental Working Group, or EWG, is responsible for singling out produce with the highest content of pesticide levels. This updated 2015 Dirty Dozen list is helpful for those who can’t always afford to buy 100 percent of their food in the organic section. So, if you have to pick how many organic foods enter your shopping cart, choose from this list:
- Sweet bell peppers
- Cherry tomatoes
- Imported snap peas
According to the EWG website, the following were key findings:
- 99 percent of apple samples, 98 percent of peaches, and 97 percent of nectarines tested positive for at least one pesticide residue.
- The average potato had more pesticides by weight than any other produce.
- A single grape sample and a sweet bell pepper sample contained 15 pesticides.
- Single samples of cherry tomatoes, nectarines, peaches, imported snap peas and strawberries showed 13 different pesticides apiece.
For the third straight year, the EGW expanded the Dirty Dozen list with a plus category highlighting two types of food that contain trace levels of dangerous pesticides. Leafy greens, including kale and collard greens, and hot peppers did not meet traditional Dirty Dozen ranking criteria but were found to be contaminated with insecticides toxic to the nervous system.
The Clean Fifteen List
Along with a list of “dirty” foods, the EWG also searches for the cleanest non-organic foods. If you have to let a few non-organic foods slide, these might be good candidates:
- Sweet corn
- Frozen sweet peas
- Sweet potatoes
The EWG found that relatively few pesticides were detected on these foods. Key highlights of the Clean Fifteen list included the following, according to the EWG website:
- Avocados were the cleanest for the second year in a row; only 1 percent of avocado samples showed any detectable pesticides.
- Some 89 percent of pineapples, 82 percent of kiwi, 80 percent of papayas, 88 percent of mango and 61 percent of cantaloupe had no residues.
- No single fruit sample from the Clean Fifteen list tested positive for more than 4 types of pesticides.
- Multiple pesticide residues are extremely rare on Clean Fifteen vegetables. Only 5.5 percent of Clean Fifteen samples had two or more pesticides.
Crinnion, W. (2010). Organic foods contain higher levels of certain nutrients, lower levels of pesticides, and may provide health benefits for the consumer. Alternative Medicine Review.
Mnif, W., Hassine, A., Bouaziz, A., Bartegi, A., Thomas, O., & Roig, B. (2011). Effect of Endocrine Disruptor Pesticides: A Review. International Journal of Environmental Research and Public Health, 2265-2303.
Stewart, K. (2007). Eating between the lines: The supermarket shopper's guide to the truth behind food labels. New York: St. Martin's Griffin.