Deposition patterns of non-exhaust emissions on Taraxacum officinale as a potential urban biomonitor

Keywords: Biomonitoring, trace metals, non-exhaust
Abstract Type: Poster Abstract

Abstract

In this paper, we examine if Taraxacum officinale can function as an urban biomonitor for non-exhaust vehicle emissions in Mississauga, Ontario. Specifically, we measure concentrations of cadmium, copper, lead, cadmium, arsenic and zinc from brake dust and tire wear. We report on the deposition patterns of arsenic and cadmium and found 22.92 ug/g of arsenic and 9.20ug/g of cadmium in samples within 300m of the Ontario 403 freeway. Samples within 300m of the major highway, Dixie Road had 17.75ug/g of arsenic and 3.15 ug/g of cadmium. Samples within a residential subdivision had 11.54 ug/g of arsenic and 2.13ug/g of cadmium. These findings suggest that as the distance increases from the major freeway, the ground-level concentrations decline at the receptors. Flowers from Taraxacum officinale were obtained in 1 m square plots using the same distance intervals from the highway. Trace metal concentrations were obtained after drying the leaf material at 55 degrees for 2 hours and then 0.2 grams of dry material were ground-up to a powder using a mill. The leaves underwent acid digestion, and an inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to perform the trace metal analysis. This analysis produces a chemical breakdown in which the origin and concentration of the different particulates can be identified and compared to an RLINE dispersion model. This work expands the field of biomonitoring to explore the effectiveness of Taraxacum officinale as a biomonitor for non-exhaust emissions in Mississauga, Ontario.