Assessment of insecticide risk quantification methods: Introducing the Pesticide Risk Tool and its improvements over the Environmental Impact Quotient

Tools for quantifying nontarget pesticide risks have long been used for documenting the benefits of Integrated Pest Management (IPM) programs. One resource receiving little attention is the Pesticide Risk Tool (PRT), developed by the IPM Institute in Madison, WI. The PRT includes 15 indices and uses a probabilistic approach to assess the risk for the environmental and human health effects of insecticides, fungicides, and herbicides. In this article, we compare the PRT to the Environmental Impact Quotient (EIQ) to highlight the PRT's approach to characterizing risk and several improvements over the EIQ. Comparing the calculated risk scores between the EIQ and PRT shows a similar trend with organophosphate insecticides, usually reflecting the highest toxicity risks, with more pronounced differences for pyrethroids and neonicotinoids, but exact toxicity rankings differ. Advantages of the PRT over the EIQ include the probabilistic approach to quantify risk and reliance on field impact data where available, the use of raw data for inputs versus a scoring system, correction of known issues with the EIQ, and its greater diversity of risk indices. Some disadvantages of the PRT include its lack of data on discontinued products, the absence of a total risk score, use of different scoring scales between indices, and its cost. However, given the pros and cons of each method, we believe the PRT to be a useful tool for researchers, extension professionals, and growers who wish to account for environmental and human health risks when building IPM programs.