übertool: web applications for ecological risk assessment (beta version)
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Cloud-based environmental models used by the USEPA for evaluating pesticide risks to ecosystems under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Endangered Species Act (ESA).
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T-Herps Overview



T-HERPS is designed to estimate dietary exposure and risk to terrestrial-phase amphibians and reptiles from pesticide use. Historically, risk assessments for terrestrial-phase amphibians and reptiles have been estimated from models using avian toxicity data. T-HERPS was developed to more accurately estimate amphibian and reptile exposure risk by including lower metabolic rates and dietary requirements that are associated with poikilothermic organisms. When terrestrial-phase amphibian or reptile data is unavailable, avian toxicity data can be used in T-HERPS although output estimates should be interpreted cautiously.

 

An allometric function in T-HERPS allows for food intake to be estimated from the body size of the study animal. The associated equation is based on food ingestion rates of an iguanid lizard, an insectivorous reptile with dietary habits similar to the California red-legged frog, and therefore should not be used for strictly herbivorous reptiles and amphibians. For species that consume larger prey, such as other amphibians, reptiles or small mammals, alternative methods for determining EECs are included in T-HERPS.

 

Food intake estimates are provided in units of kg-diet/day by size class (small, medium, large). Daily doses of pesticides to the study animal are given in units of mg/kg – bw by size class and food type. Using the daily dose estimates, T-HERPS calculates the mass of the pesticide potentially consumed for EEC determinations. Input estimates of food water content are required for calculation of pesticide intake.