Biomonitoring of Ramalina farinacea lichens deployed in Seattle, Washington via sequential extraction of metals
Research Mentor(s)
Sofield, Ruth M.
Description
To evaluate the heterogeneity of metal accumulation in lichens exposed to varying amounts of industrial pollution in the field, a sequential extraction was performed on Ramalina farinacea lichens deployed at nine locations in Seattle, Washington. Lichens were initially collected from the Sehome Arboretum in Bellingham, Washington and then suspended in nylon bags for two and then twelve weeks to pick up airborne metals. After the exposure periods, EDTA was used as a chelating agent in a sequential extraction to analyze the varying amounts and ratios of water soluble non-bound metals, extracellular metals, and intracellular metals. Lichen samples were then digested and analyzed to quantify residual particulate metals. Metals in the extracellular fraction are thought to be indicators of recent atmospheric metal deposition, while metals in the intracellular and residual fractions indicate long term metal deposition and integration into the lichen thalli. Differences in fractionation and amounts of accumulated metals serve as an indicator of amount and timing of metal pollution at the different exposure sites, supporting lichen biomonitoring as an effective way to characterize metal pollution. Results collected to date will be presented.
Document Type
Event
Start Date
16-5-2018 9:00 AM
End Date
16-5-2018 12:00 PM
Department
Environmental Sciences
Genre/Form
student projects, posters
Subjects – Topical (LCSH)
Environmental monitoring--Washington (State)--Seattle; Air quality--Washington (State)--Seattle--Measurement; Ramalina
Geographic Coverage
Seattle (Wash.)
Type
Image
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.
Language
English
Format
application/pdf
Biomonitoring of Ramalina farinacea lichens deployed in Seattle, Washington via sequential extraction of metals
To evaluate the heterogeneity of metal accumulation in lichens exposed to varying amounts of industrial pollution in the field, a sequential extraction was performed on Ramalina farinacea lichens deployed at nine locations in Seattle, Washington. Lichens were initially collected from the Sehome Arboretum in Bellingham, Washington and then suspended in nylon bags for two and then twelve weeks to pick up airborne metals. After the exposure periods, EDTA was used as a chelating agent in a sequential extraction to analyze the varying amounts and ratios of water soluble non-bound metals, extracellular metals, and intracellular metals. Lichen samples were then digested and analyzed to quantify residual particulate metals. Metals in the extracellular fraction are thought to be indicators of recent atmospheric metal deposition, while metals in the intracellular and residual fractions indicate long term metal deposition and integration into the lichen thalli. Differences in fractionation and amounts of accumulated metals serve as an indicator of amount and timing of metal pollution at the different exposure sites, supporting lichen biomonitoring as an effective way to characterize metal pollution. Results collected to date will be presented.