Presentation Abstract

Assessing the risks posed by chemical mixtures is a complex process. Ideally, details are available on exposure (e.g. which chemicals and what concentrations) and effects (e.g. mechanisms of action and toxicity data). This can be challenging even for a single location and time such as a lab or field site. Ecological risk assessments often need to cover much larger scales such as an entire watershed or a wide-ranging species. This increase in scale substantially increases the complexity. Thousands of chemicals in use lead to potential environmental mixture exposures, including pesticide runoff and municipal wastewater discharges. At the landscape scale the nature of chemical mixtures will vary across space and time; available monitoring data are inadequate for describing realistic exposure scenarios and effects on aquatic species. Therefore, creative solutions are required to utilize sources of data that are available to identify where and when risk is the greatest. Sources of data are available to develop a less-detailed, but still useful, landscape scale risk assessment for mixtures. These include data on potential use (e.g. pesticide labels) or release (e.g. mapping of NPDES permits) sites, as well as associated land use/cover. For example, the use of crop designations to represent where pesticide use is allowed can be a surrogate of actual use to establish where the greatest potential for exposure occurs. This landscape scale risk assessment for mixtures can establish priority watersheds for monitoring and further study. Similarly, exposure of aquatic species to complex mixtures discharged in wastewater can be related to urban land uses and permit distributions. The goal is to develop a process to prioritize the areas with increased relative risks of exposure to chemical mixtures in aquatic species and identify important data needs necessary for more detailed mixture analyses in the context of a landscape scale risk assessment.

Session Title

Posters: Fate, Transport, & Toxicity of Chemicals

Keywords

GIS, Pesticides, Risk, Aquatic

Conference Track

SSE18: Posters

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE18-64

Start Date

5-4-2018 11:30 AM

End Date

5-4-2018 1:30 PM

Type of Presentation

Poster

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 5th, 11:30 AM Apr 5th, 1:30 PM

Assessing the impacts of toxic mixtures over a broad geographic scale: challenges and first steps

Assessing the risks posed by chemical mixtures is a complex process. Ideally, details are available on exposure (e.g. which chemicals and what concentrations) and effects (e.g. mechanisms of action and toxicity data). This can be challenging even for a single location and time such as a lab or field site. Ecological risk assessments often need to cover much larger scales such as an entire watershed or a wide-ranging species. This increase in scale substantially increases the complexity. Thousands of chemicals in use lead to potential environmental mixture exposures, including pesticide runoff and municipal wastewater discharges. At the landscape scale the nature of chemical mixtures will vary across space and time; available monitoring data are inadequate for describing realistic exposure scenarios and effects on aquatic species. Therefore, creative solutions are required to utilize sources of data that are available to identify where and when risk is the greatest. Sources of data are available to develop a less-detailed, but still useful, landscape scale risk assessment for mixtures. These include data on potential use (e.g. pesticide labels) or release (e.g. mapping of NPDES permits) sites, as well as associated land use/cover. For example, the use of crop designations to represent where pesticide use is allowed can be a surrogate of actual use to establish where the greatest potential for exposure occurs. This landscape scale risk assessment for mixtures can establish priority watersheds for monitoring and further study. Similarly, exposure of aquatic species to complex mixtures discharged in wastewater can be related to urban land uses and permit distributions. The goal is to develop a process to prioritize the areas with increased relative risks of exposure to chemical mixtures in aquatic species and identify important data needs necessary for more detailed mixture analyses in the context of a landscape scale risk assessment.