Accumulation Characteristics of Metals and Metalloids in Plants Collected from Ny-Ålesund, Arctic

Hongmei Ma,Guitao Shi,Yongqian Cheng

doi:10.3390/atmos11101129

Abstract

Toxic elements can be transported to polar regions by long-range atmospheric transport from mid and low latitudes, leading to enrichment of elements in the polar environment, especially in the Arctic. The plants can be ideal bioindicators of element contamination in environments, but information on the element enrichment and sources of plants remains limited in polar regions. Here, concentrations of 15 metals and metalloids (Pb, Ni, Cr, Cu, Co, As, Cd, Sb, Hg, Se, Fe, Zn, Mn, Al, and Ti) in six species of plants, Deschampsia caespitosa (Tufted Hair Grass), Puccinellia phryganodes (Creeping Alkaligrass), Saxifraga aizoides (Yellow Mountain Saxifrage), Dicranum angustum (Dicranum Moss), Salix Polaris (Polar Willow), and Cerastium arcticum (Arctic Mouse-Ear Chickweed), collected from Ny-Ålesund, the Arctic, were determined, and enrichment and sources of elements were assessed. Results show that element concentrations vary in different plant species, and element levels in D. angustum and C. arcticum are generally higher. In spatial terms, elevated element concentrations were found near residential areas, while low element levels were present at the sites far from settlement points. Enrichment assessment shows that Cd, Hg, and Zn are the most enriched elements, with enrichment factors above 30, suggesting sources other than soil dust control their concentrations. Principal component analysis (PCA) showed that the extracted three components can explain 82% of the total variance in element concentrations. The elements Ni, Cr, As, Sb, Fe, Al, Ti, and to a lesser extent Co are highly loaded in PC1, possibly associated with continental crust particles. PC2 is closely correlated with Cd, Se, Mn, Cu, and Zn, while Hg and Pb have high loadings on PC3. The elements highly loaded on PC2 and PC3 are likely associated with pollutants from atmospheric transportation. Together with enrichment assessment, the investigated plants have a great potential for monitoring atmospheric Cd, Hg, and Zn pollution in Ny-Ålesund, and D. angustum and D. caespitosa are the more sensitive species. The results would be of significance for monitoring element contamination in the pristine Arctic environments using the bioindicator plants.

Highlights

The pristine Arctic has become a region of great concern, and growing evidence has indicated that anthropogenic contaminants can reach the remote Arctic from mid and low latitudes via long-distance atmospheric transport [1,2,3,4,5,6]
It is noted that element concentrations in this study are comparable to those in Canadian High Arctic
While few samples were collected from individual species, the measurements provide the general information on element accumulation status in Arctic plants

Summary

Introduction

The pristine Arctic has become a region of great concern, and growing evidence has indicated that anthropogenic contaminants (e.g., heavy metals) can reach the remote Arctic from mid and low latitudes via long-distance atmospheric transport [1,2,3,4,5,6]. In the Arctic, increased contaminant concentrations have. Atmosphere 2020, 11, 1129 been found in varied environmental compartments, such as atmosphere, snow, soil, and sediment [7,8,9,10,11,12]. Mercury (Hg) has been attracting more attention, considering that Hg, once deposited, can be methylated by bacterial activities and becomes bioavailable to organisms, subsequently potentially affecting the ecosystems [13,14]. Similar to Hg, other potentially toxic metals, such as lead (Pb) and cadmium (Cd), can biomagnify via the food chain, and accumulate in living organisms [15]. The investigations on occurrence, concentrations, and distribution patterns of toxic metals in the Arctic ecosystem are critical to evaluate to what extent human emissions influence this pristine environment.

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