PROBLEM: Mycotoxins, produced by fungi that infect food crops, cause human and animal disease and economic loss to farmers. Insects that feed on foods create infection entry points. Bt corn, because of its protection against insect pests, secondarily reduces fungal infection. Evidence abounds that Bt corn has lower levels of the mycotoxin fumonisin than non-Bt isolines. But past field studies have reached no conclusion on whether Bt corn reduces aflatoxin. Whether Bt corn could reduce aflatoxin is crucial from food safety and economic standpoints.NOVELTY: We will use large datasets from the USDA Risk Management Agency, NOAA, and agricultural surveys to determine whether Bt corn planting has resulted in fewer aflatoxin-related insurance claims in the US. We hypothesize that Bt corn planting reduces aflatoxin risk. To test this hypothesis and study its implications, we propose two OBJECTIVES:1. Develop a predictive model linking aflatoxin-related insurance claims to Bt corn planting intensity, climatic variables, grower practices, and their interactions.2a: Estimate economic impacts of Bt corn planting attributable to reduced aflatoxin.2b: Estimate aflatoxin risk in "stress tests" of future potential temperature/drought conditions, and how Bt events could reduce risk.IMPACT: This novel research method, examining a food safety problem tracked by agricultural insurance claims, will determine whether Bt corn planting can indeed reduce aflatoxin in US corn. It may incentivize growers most at risk, primarily in Southern states, to better manage and protect extant and new Bt toxins. Our method can be applied to examine other US food safety concerns.