How does your job support modern agriculture in America?
It’s a fact that there are a lot of people in this world (7 billion as of 2011) and it will only get more crowded. By 2050, the world population will grow to nearly 9 billion people.1 That’s a lot of hungry mouths to feed. Modern agriculture will be responsible for feeding them high quality foods by improving capacity as much as 70 percent or more in the next four decades.2 These demands will also face challenges in protecting the environment, changing climates and social-economic factors. This will be accomplished by using safe, innovative and effective crop protection products to control the 30,000 species of weeds and 10,000 species of plant-eating insects. My job is to make sure crops grown by farmers using pesticides are safe for human consumption not just for adults, but for our most important population: infants and children. I am a Dietary Risk Assessment Expert and my role is to make sure modern agriculture has safe products to use.
Estimating dietary risk is not magic, but relies on a simple equation: Risk = Hazard x Exposure. This means a chemical with a low hazard (i.e. salt) which has excessive exposure may pose as much risk as chemicals with high toxicity and limited exposure. Determining dietary exposure is a function of how much of a given food you eat (grams food/kilogram body weight) times how much residue is on that food (milligram a.i./kilogram food). EPA establishes tolerances, or the maximum residue limit (MRL), representing the allowable pesticide residue on foods. EPA requires our industry to show the tolerances are “safe” by presenting “reasonable certainty that no harm will result from aggregate exposure to the pesticide residue.” Complex probabilistic models are used to simulate the dietary exposure of a population of individuals for a 365 day period. These models rely on real-world consumption survey data from the USDA which tell us what foods people eat on a daily basis. Residue data distributions from field trials conducted according to the label or monitoring programs (USDA Pesticide Data Program) are randomly assigned to these foods. To make the simulation realistic, percent crop treated data is used since not all fields are applied with a specific pesticide. Also, processing factors, such as washing and cooking that may reduce residues or juicing that may concentrate residues, are applied to simulate exposure on your dinner plate. The probabilistic model estimates a distribution of dietary exposures for a given population. The exposure value at the extreme end of the distribution (99.9th percentile) is compared with the hazard value factoring in a 100-fold safety factor. If the exposure is less than this hazard value, the use is safe; however, exceeding the hazard value indicates risk requiring mitigation and/or removing use patterns.
My job as a dietary risk assessment expert is essential to modern agriculture. Without EPA regulations like the Food Quality Protection Act of 1996, there would be no way to ensure that it is safe to feed children food grown using modern agriculture (USDA PDP reports only 0.25 percent samples exceeded established tolerance).3 Without the exposure-based approach used to determine dietary risk, we would simply ban pesticides based on toxicity values or residue levels, limiting the number of crop protection products a farmer can use. Without the collaborative efforts of the industry with EPA to develop and validate these complex exposure models, modern agriculture would not be able to use safe and innovative products. This would result in a decrease of 20 to 50 percent in crop productivity and increase the cost of food by nearly 48 percent.4 That’s a lot of unhappy hungry people. I’m glad to be part of the solution.
1 – http://www.worldometers.info/world-population/
2 – Motes, William. 2010. Modern Agriculture and Its Benefits – Trends, Implications and Outlook. Global Harvest Initiative. http://www.globalharvestinitiative.org/Documents/Motes%20-%20Modern%20Agriculture%20and%20Its%20Benefits.pdf
3 – USDA Pesticide Data Program (PDP). http://www.ams.usda.gov/AMSv1.0/ams.fetchTemplateData.do?template=TemplateC&navID=PesticideDataProgram&rightNav1=PesticideDataProgram&topNav=&leftNav=ScienceandLaboratories&page=PesticideDataProgram&resultType
4 – CropLife America. 2012. Communicating the Safety of Our Healthy Produce – User Toolkit. http://tellmemore.croplifeamerica.org/wp-content/uploads/2012/07/CLA_Toolkit_Links4.pdf
Research Triangle Park, NC