Ecological Modeling of Pesticide Risks to Non-Target Organisms

Corn Rows in Tennessee

Cardno provides ecological modeling support in assessing risks posed by pesticide products.

Syngenta Crop Protection, LLC thoroughly evaluates the potential ecological impacts associated with the application of its pesticide products. The company manufactures active ingredients that are applied to important crops – including corn and soybean – throughout the United States and worldwide, including atrazine, one of the most widely used pesticides to protect corn and soybean from weed infestation.

Cardno worked with Syngenta to provide quantitative ecological risk assessments for atrazine applications in the Midwestern corn belt. Atrazine has the potential to runoff from cultivated fields and enter adjacent surface waters where non-target aquatic plants, fish, and other organisms can be exposed and potentially impacted if exposure concentrations are sufficiently high and for extended durations.

Cardno implemented the comprehensive aquatic system model (CASM) to assess the potential ecological risks posed by atrazine, including:

  • Construction of an aquatic food web representative of lower-order Midwestern streams subject to atrazine runoff
  • Collation of data describing toxicity of atrazine to aquatic plants, invertebrates, and fish
  • Development of exposure scenarios for atrazine applications for selected locations throughout the Midwest corn belt

In addition, Cardno performed CASM simulations of the potential direct and indirect ecological effects of atrazine for each exposure scenario and provided a detailed report on the risk assessment results.

The CASM ecological modeling approach and results for atrazine were subject to peer review and evaluation by a United States Environmental Protection Agency independent Science Advisory Panel. The CASM atrazine risk modeling has been presented at several annual meetings of the Society for Environmental Toxicology and Chemistry and published in the peer-reviewed technical literature.

Cardno continues to provide CASM ecological modeling support in assessing risks posed by other Syngenta active ingredients, including the neonicotinoid pesticide, thiamethoxam. Recent applications include paring CASM with individual based models for the purposes of endangered species risk assessment.