Environ Int. 2016 Jul-Aug;92-93:494-506. doi: 10.1016/j.envint.2016.03.018. Epub 2016 May 10.
- 1Department of Renewable Resources, University of Alberta, Canada. Electronic address: shotyk@ualberta.ca.
- 2Department of Renewable Resources, University of Alberta, Canada. Electronic address: bicalho@ualberta.ca.
- 3Department of Renewable Resources, University of Alberta, Canada. Electronic address: cuss@ualberta.ca.
- 4SLOWPOKE Nuclear Reactor Facility, University of Alberta, Canada. Electronic address: mjduke@ualberta.ca.
- 5Department of Renewable Resources, University of Alberta, Canada. Electronic address: noernber@ualberta.ca.
- 6Department of Renewable Resources, University of Alberta, Canada. Electronic address: rickp@ualberta.ca.
- 7Department of Chemistry, Norwegian University of Science and Technology, Norway. Electronic address: eiliv.steinnes@ntnu.no.
- 8Department
of the Sciences of Agriculture, Food and Environment, University of
Foggia, Italy. Electronic address: claudio.zaccone@unifg.it.
Abstract
Sphagnum
fuscum was collected from twenty-five ombrotrophic (rain-fed) peat bogs
surrounding open pit mines and upgrading facilities of Athabasca
Bituminous Sands (ABS) in northern Alberta (AB) in order to assess the
extent of atmospheric contamination by trace elements. As a control,
this moss
species was also collected at a bog near Utikuma (UTK) in an undeveloped
part of AB and 264km SW of the ABS region. For comparison, this moss
was also collected in central AB, in the vicinity of the City of
Edmonton which is approximately 500km to the south of the ABS region,
from the Wagner Wetland which is 22km W of the City, from Seba Beach
(ca. 90km W) and from Elk Island National Park (ca. 45km E). All of the moss
samples were digested and trace elements concentrations determined
using ICP-SMS at a commercial laboratory, with selected samples also
analyzed using instrumental neutron activation analysis at the
University of Alberta. The mosses from the ABS region yielded lower
concentrations of Ag, As, Bi, Cd, Cu, Pb, Sb, Tl, and Zn compared to the
moss from the
Edmonton area. Concentrations of Ni and Mo in the mosses were comparable
in these two regions, but V was more abundant in the ABS samples.
Compared with the surface vegetation of eight peat cores collected in
recent years from British Columbia, Ontario, Quebec and New Brunswick,
the mean concentrations of Ag, As, Bi, Cd, Cu, Mo, Ni, Pb, Sb, Tl and Zn
in the mosses from the ABS region are generally much lower. In fact,
the concentrations of these trace elements in the samples from the ABS
region are comparable to the corresponding values in forest moss
from remote regions of central and northern Norway. Lithophile element
concentrations (Ba, Be, Ga, Ge, Li, Sc, Th, Ti, Zr) explain most of the
variation in trace metal concentrations in the moss samples. The mean concentrations of Th and Zr are greatest in the moss
samples from the ABS region, reflecting dust inputs to the bogs from
open pit mines, aggregate quarries, and gravel roads. Linear regressions
of V, Ni, and Mo (elements enriched in bitumen) versus Sc (a
conservative, lithophile element) show excellent correlations in the
mosses from the ABS region, but this is true also of Ag, Pb, Sb and Tl:
thus, most of the variation in the trace metal concentrations can be
explained simply by the abundance of dust particles on the plants of
this region. Unlike the moss samples from the ABS region and from UTK where Pb/Sc ratios resemble those of crustal rocks, the moss
samples from the other regions studied yielded much greater Pb/Sc
ratios implying significant anthropogenic Pb contributions at these
other sites.
Copyright © 2016 Elsevier Ltd. All rights reserved.
KEYWORDS:
Athabasca Bituminous Sands; Heavy metals; Molybdenum; Nickel; Sphagnum moss; Vanadium
