Cynthia L. Curl, PhD
Cynthia L. Curl, PhD, assistant professor, department of community and environmental health, Boise State University, Idaho. Her study appeared in Environmental Health Perspectives.
Why pay $2 more for an organic head of broccoli that’s half the size of a conventionally grown one? If you prefer organic fruits and vegetables to conventionally grown produce, you probably mainly do so to avoid pesticide exposure…or you may be on the fence about whether eating organic is worth it. After all, the government closely inspects produce for pesticide residue to make sure that levels are negligible. A new study, however, provides important evidence that may convince you to go organic.
Roughly one billion pounds of pesticides are used on crops in the United States each year to protect them from insects and parasites. One class of compounds, called organophosphates, represents the most commonly used insecticides in the United States. Although organophosphates do not accumulate in the environment, residues of these compounds still turn up in conventionally grown produce—and in your own body, either because of diet or environmental exposure in the form of living downwind or downstream of where organophosphates are used. Limits of how much of this residue in food is “reasonably harmless” are set by the Environmental Protection Agency (EPA), the US Department of Agriculture (USDA) and other government agencies.
Enter a team of environmental health and epidemiology specialists from the University of Washington, Harvard and the University of Texas Health Science Center. They developed a method to estimate how much organophosphate residue a person has been exposed to through diet and also compared organophosphate residue levels in people who eat conventionally grown produce with those in people who mostly eat organic.
Methods of measuring organophosphate residue in the human body do exist, but they are imprecise, in part because the residues from any given food item clear the body through urine within two days. To make sense of the measurements that may admittedly be imperfect, the latest research correlated information gleaned from the established technique with carefully collected information about the eating habits of 4,500 middle-aged and older people from across the United States.
In particular, the team gathered data on how often certain foods were eaten, the serving size of those foods and how often organic produce was chosen. The information was combined with information from a USDA database that meticulously quantifies how much and specifically which pesticide residues are in 95 food items, including fruits, vegetables and juices. (You can access this raw data and annual summaries of the data through the USDA website.)
The researchers sliced and diced their study population in different ways and compared estimated levels of organophosphate residue exposure based on diet with actual measurements of organophosphate residue in their urine.
The results: People who mostly eat organic were exposed to organophosphate residues an average 35% less than people who primarily consumed conventionally grown produce. Not surprisingly, the more conventional versus organic produce a person ate, the higher the amount of organophosphate residue measured in urine. “The levels of pesticide residues in the urine samples did not suggest unacceptable risk, based on current risk standards. However, many researchers suspect that concerns about low-level risk may arise if the EPA begins to evaluate exposure risk based on more sensitive scientific methods,” the lead author of the study, Cynthia Curl, PhD, assistant professor in the department of community and environmental health at Boise State University, told Daily Health News.
Although the EPA and the CDC have said that organophosphate residues in the US food supply are harmless, the long-term impact is actually unknown. Consider that straight-on long-term exposure to organophosphate pesticides among farmers and others who work with these chemicals has been associated with confusion, anxiety, memory loss and depression—symptoms similar to dementia. Associations between occupational exposure to organophosphates and neuromuscular problems, lymphoma and leukemia have been made as well. Think about it…is saving money on cheaper produce worth the potential risk to your health?
