Global use of the Environmental Impact Quotient: A tool to indicate potential pesticide risk

The Environmental Impact Quotient (EIQ) is a weighted, multi-component pesticide risk indicator (PRI) developed in 1992 by the New York State Integrated Pest Management Program (NYSIPM) at Cornell University. It serves as a decision-support tool to help growers, educators, and policymakers choose less hazardous pesticide options for farm workers, consumers, and non-target organisms. This systematic review presents data from 113 studies published between 1992 and 2024, along with Google Analytics metrics from the EIQ website, on the global use of the EIQ. Our findings indicate that the EIQ has been widely adopted, particularly in North America, and is commonly used to compare the application of Integrated Pest Management (IPM) strategies or the implementation of genetically modified crops. The EIQ is also used to track potential pesticide risk through time and across different localities. Corn, cotton, tomato, wheat, and soybeans are the crops with the highest number of studies implementing the EIQ. The EIQ has been compared to other PRIs and shows strong agreement with those incorporating similar environmental compartments. Many authors report selecting the EIQ over other PRIs due to its straightforward implementation across diverse systems. We also highlight the limitations of the EIQ, including the asymmetric weighting of its components, the limited scoring system, and the high correlation with the application rate. Recently, the NYSIPM introduced a wider scoring system to the EIQ based on institutional hazard classifications. While the EIQ remains a widely used tool, structural updates are needed to maintain its relevance and improve its performance.