Bioavailability of arsenic and antimony in soils from an abandoned mining area, Glendinning (SW Scotland)

Abstract

The mobility and bioavailability of As and Sb in relation to soil-biota transfer were evaluated at a former Sb mining and smelting site (Glendinning, SW Scotland, UK). The study specifically assessed the accumulation of As and Sb in different environmental components (soil, plants and earthworms) across mining area to estimate risk factors for the biota. Total concentrations and fractions of As and Sb in soils were determined. The latter using both a single solute and a non-specific stepwise sequential extraction (CISED) method. Mineralogical information was gathered from XRD and SEM analysis used to identify element distribution patterns. Pseudo-total (aqua-regia) levels of As and Sb in the soils varied between 50-17,400 mg kg(-1) and 10-1,200 mg kg(-1), respectively. Both elements are predominantly associated with Fe (or Al) oxides/hydroxides, by adsorption around silicate grains, representing a potentially bioavailable fraction. Antimony was also associated with sulphide phases. The highest values of As and Sb in biota were recorded in the earthworms (960 mg kg(-1) and 27 mg kg(-1), respectively). Bioconcentration factors for both elements were below 1 and the highest for earthworms. Total and leached As levels in soils and biota were positively and significantly correlated, but only for Sb in earthworms and grass. Bioavailability of As in the biota, was shown to be limited by pH. In spite of the considerably high As and Sb contents of the soil the plant contamination remained comparably low, but still exceeded background values.

Antimony mobility in lead smelter-polluted soils

“…However, only a few studies in the literature were devoted to differences in uptake of Sb and As by plants. One study in a mine contaminated area in Glendinning, Scotland showed that Sb was proportionally more available, whereas biological uptake by plants (ferns and grass) and earthworms was higher for As (Gál et al, 2007). In contrast, our chemical fractionation data show that Sb at the Příbram site was found to be chemically less mobile (Figs.…”

“…The application of SEP on polluted soil and sediment samples from Mansfeld District, Germany, showed that up to 18% of the As and 12% of the Sb was extracted in the first step, corresponding to the "mobile" fraction (Müller et al, 2007). The only contrasting results were found in soils from an old mining area in Glendinning, Scotland, where 1 mol l − 1 NH 4 NO 3 extraction yielded higher amounts of mobile Sb (0.01-8.8% of total Sb) than mobile As (0.01-0.6% of total As) (Gál et al, 2007).…”

“…In the past decade, we have been able to observe an increasing interest of geochemists in the cycling and behaviour of Sb, which is now classified as an "emerging" contaminant. Numerous studies have been devoted to Sb distribution and availability in less and moderately contaminated soils and sediments (Nakamaru et al, 2005;Tighe et al, 2005a;Tighe and Lockwood, 2007) and in particular in those strongly affected by anthropogenic activities, such as in shooting ranges (Knechtenhofer et al, 2003;Johnson et al, 2005;Ackermann et al, 2009), mining and smelting areas (Flynn et al, 2003;He, 2007;Müller et al, 2007;Ettler et al, 2007;Gál et al, 2007;Telford et al, 2008) and in the vicinity of roads (Amereih et al, 2005). The geochemical behaviour of Sb is generally assumed to be similar to that of another toxic metalloid, As (Tighe et al, 2005b).…”

Mobility of antimony, arsenic and lead at a former antimony mine, Glendinning, Scotland

“…Ore smelting took place at Jamestown, ~1 km downhill of the mine (Gallagher et al, 1983). Several spoil heaps in the vicinity of the mine are still evident, and previous studies have reported Sb concentrations of 14.0-673 mg kg −1 (Flynn et al, 2003) and 10.3-1200 mg kg −1 (Gál et al, 2007) in the surrounding soils. Whilst these studies demonstrated that the soil Sb concentrations were significantly elevated above background levels, the geochemical associations, lateral and vertical elemental mobility and transport mechanisms for Sb, As and Pb at the site remain poorly defined.…”

“…Significant environmental and human health impacts are associated with on-going ore extraction and smelting processes but there are also environmental concerns relating to historical sites. In the UK, Sb mining and smelting activities ceased in the mid-20th century (Flynn et al, 2003) but impacts upon soils and waters are still observed in the 21st century (Flynn et al, 2003;Gál et al, 2007). In addition, Sb mining and smelting processes usually release arsenic (As) and lead (Pb) to the environment since all three elements commonly co-occur in the sulfidic ore deposits.…”