Presentation Abstract

Two highly toxic trace metals, silver (Ag) and cadmium (Cd) have been monitored in the sediments and water column of the Strait of Georgia since 2014. With the advent of nanotechnology, silver nanoparticles are widely used in medical applications and consumer products, and inevitably being discharged into the environment. Cd is of particular concern in the coastal waters of B.C. due to its naturally high concentration in the incoming Pacific water and possible anthropogenic sources. The sediment profile of a core taken near the Iona Island wastewater treatment plant outfall showed rising levels of both Ag and Cd in the upper 25 cm, which could be attributed to the start of effluent discharge through deep water diffusers in 1988. To confirm whether the Iona outfall is a significant point source, weekly effluent samples from Iona were analyzed for dissolved and total Ag and Cd over a year. Our results showed that the average dissolved Ag measured in the effluent is about 100 times higher than its expected concentration in the incoming Pacific water; whereas dissolved Cd concentrations are more variable, but in the same order of magnitude as in the Pacific water. Preliminary analysis using a steady-state box model of the Strait of Georgia suggests that the Iona outfall minimally impact the Cd level in the water column of the Strait, but could slightly enhance its dissolved Ag concentration. Ongoing time-series measurement of the concentrations of dissolved and particulate Ag and Cd in the Strait will provide further information on their temporal variability, sinking flux to the sediments, and bioaccumulation.

Session Title

Posters: Fate, Transport, & Toxicity of Chemicals

Keywords

Toxic trace metals, sources, dispersion and removal, Strait of Georgia

Conference Track

SSE18: Posters

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE18-58

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

Dispersion and removal of two toxic trace metals (Ag and Cd) in the Strait of Georgia

Two highly toxic trace metals, silver (Ag) and cadmium (Cd) have been monitored in the sediments and water column of the Strait of Georgia since 2014. With the advent of nanotechnology, silver nanoparticles are widely used in medical applications and consumer products, and inevitably being discharged into the environment. Cd is of particular concern in the coastal waters of B.C. due to its naturally high concentration in the incoming Pacific water and possible anthropogenic sources. The sediment profile of a core taken near the Iona Island wastewater treatment plant outfall showed rising levels of both Ag and Cd in the upper 25 cm, which could be attributed to the start of effluent discharge through deep water diffusers in 1988. To confirm whether the Iona outfall is a significant point source, weekly effluent samples from Iona were analyzed for dissolved and total Ag and Cd over a year. Our results showed that the average dissolved Ag measured in the effluent is about 100 times higher than its expected concentration in the incoming Pacific water; whereas dissolved Cd concentrations are more variable, but in the same order of magnitude as in the Pacific water. Preliminary analysis using a steady-state box model of the Strait of Georgia suggests that the Iona outfall minimally impact the Cd level in the water column of the Strait, but could slightly enhance its dissolved Ag concentration. Ongoing time-series measurement of the concentrations of dissolved and particulate Ag and Cd in the Strait will provide further information on their temporal variability, sinking flux to the sediments, and bioaccumulation.