Evaluating Concentrations of Pesticides and Heavy Metals in the U.S. Peanut Crop in the Presence of Detection Limits

Abstract

The concentration of mercury, cadmium, lead, and arsenic along with glyphosate and an extensive array of pesticides in the U.S. peanut crop was assessed for crop years 2013-2015. Samples were randomly selected from various buying points during the grading process. Samples were selected from the three major growing regions in order to attain a representative sample of U.S. peanut production. Samples were sent to an independent laboratory for testing. Appropriate statistical techniques were used to account for censored data due to test results below detection limits. Descriptive statistics and confidence intervals for the population mean concentration are presented where possible. For heavily censored data, the probability of a random sample from the population testing below the detection limit is estimated. Overall, concentrations were found to be low relative to health standards and consistent across crop years.