The practice of agriculture first began about 10,000 years ago in the Fertile Crescent of Mesopotamia (today this area includes Iraq, Turkey, Syria and Jordan). Since plant pests can cause loss of production, people began developing ways to prevent or control pests and diseases. In those days, pests could even lead to famine. The first recorded use of insecticides was about 4500 years ago, when the Sumerians used sulphur compounds to control insects and mites. With the passage of centuries, people invented many different types of pesticides – some of which have been associated with health and environmental issues. Many of those pesticides have even been banned over the years.
The growing evidence about pesticide exposure and possible implications for human health has raised concerns in recent years. Though the government has strict policies in place to control the level of pesticides in commercial food, these limits do not consider simultaneous exposure. This type of exposure occurs when a person is exposed to two or more chemical substances at a time, which occurs in real-life conditions and may have synergistic effects. Exposure to pesticides can happen through contact with the skin, ingestion, or inhalation. Pesticides can then be metabolized, excreted, stored, or bioaccumulated in body fat. Pesticides residues have been detected in human breast milk samples, which raises concerns about prenatal exposure and adverse health effects in children.
The type of pesticide, the duration and route of exposure, and the individual health status (age, gender, individual sensitivity, nutritional deficiencies and healthy/damaged skin) are all determining factors in potential health outcomes. The impact of pesticide exposure can stay subclinical for years or decades, which means that while your body is impacted, there are no visible side effects. Toxic effects of pesticides include skin, gastrointestinal, neurological, respiratory, reproductive and endocrine problems, and increased risk of developing cancer.
Research published in the JAMA Internal Medicine Journal in November 2017 found a correlation between pesticide intake and chance of pregnancy requiring assisted reproductive technology. The study included 325 women undergoing infertility treatment with assisted reproductive technology. Participants’ diets were assessed via questionnaires and then classified as having high or low levels of pesticide residue based on reports from the US Department of Agriculture's Pesticide Data Program. This program monitors the presence of pesticides in foods sold throughout the United States. Height, weight and overall health were also measured.
The researchers found that women who ate 2.3 servings or more of fruits and vegetables with high levels of pesticide residue had an 18% lower probability of getting pregnant and a 26% lower probability of successfully giving birth, compared to women who ate less than one daily serving. Consuming fruits and vegetables with a high amount of pesticide residue was positively associated with a higher probability of loss of pregnancy. However, you should consider these outcomes with discretion, as the dietetic assessment relies entirely on memory of the participants and therefore not certain to be accurate.
You may want to reduce the amount of foods with pesticides that you eat after hearing these findings. Please note that washing and peeling cannot completely remove pesticide residue, so you should try to avoid foods with pesticides. The Pesticide Data Program (PDP) from the USDA is a national pesticide residue monitoring program that produces the most comprehensive pesticide residue database in the U.S., which you can view here. You can also visit the Environmental Working Group website for a shopping guide to pesticides in produce, which is based on information from the USDA Pesticide Testing Program and the Food and Drug Administration and includes a large number of foods and pesticides. Finally, I encourage you to visit the Department of Energy & Environmental Protection website, where you can find non-toxic alternatives and solutions for avoiding pesticides in your lawn and garden.
If you have further questions or concerns regarding pesticides in foods come to visit me to my desk. I will be glad to answer your concerns.
Karen Alexander, BSND, MSCN