Integrated Atmospheric Solutions, LLC, Cary, NC, USA.
Integral Ecology Group, Duncan, BC, Canada.
Sci Total Environ. 2019 Nov 20;692:1005-1021. doi: 10.1016/j.scitotenv.2019.07.011. Epub 2019 Jul 16.
Temporal and spatial atmospheric deposition trends of elements to the boreal forest surrounding bitumen production operations in the Athabasca Oil Sands Region (AOSR), Alberta, Canada were investigated as part of a long-term lichen bioindicator study. The study focused on eight elements (sulfur, nitrogen, aluminum, calcium, iron, nickel, strontium, vanadium) that were previously identified as tracers for the major oil sand production sources. Samples of the in situ epiphytic lichen Hypogymnia physodes were collected in 2002, 2004, 2008, 2011, 2014, and 2017 within a ~150 km radius from the center of surface oil sand production operations in the AOSR. Site-specific time series analysis conducted at eight jack pine upland sites that were repeatedly sampled generally showed significant trends of increasing lichen concentrations for fugitive dust linked elements, particularly at near-field (<25 km from a major oil sands production operation) sample locations. Multiple regional scale geostatistical models were developed and evaluated to characterize broad-scale changes in atmospheric deposition based on changes in H. physodes elemental concentrations between 2008 and 2014. Empirical Bayesian kriging and cokriging lichen element concentrations with oil sands mining, bitumen upgrading, coke materials handling, and limestone quarry/crushing influence variables produced spatial interpolation estimates with the lowest validation errors. Gridded zonal mean lichen element concentrations were calculated for the two comprehensive sampling years (2008, 2014) and evaluated for spatial and temporal change. Lichen sulfur concentrations significantly increased in every grid cell within the domain with the largest increases (44-88%) in the central valley in close proximity to the major surface oil sand production operations, while a minor nitrogen concentration decrease (-20%) in a single grid cell was observed. The areal extent of fugitive dust element deposition generally increased with significantly higher deposition to lichens restricted to the outer grids of the enhanced deposition field, reflecting new and expanding surface mining activity.
作为长期地衣生物指标研究的一部分，研究了元素在加拿大阿尔伯塔省阿萨巴斯卡油砂区（AOSR）周围的沥青生产作业对北方森林的时空大气沉积趋势。该研究集中于先前确定为主要油砂生产源示踪剂的八种元素（硫、氮、铝、钙、铁、镍、锶、钒）。2002 年、2004 年、2008 年、2011 年、2014 年和 2017 年，在 AOSR 地表油砂生产作业中心半径约 150km 范围内，采集了原地附生地衣 Hypogymnia physodes 的样本。在八个火炬松高地站点进行的特定于站点的时间序列分析表明，与浮尘相关的元素的地衣浓度呈显著增加趋势，特别是在近场（距离主要油砂生产作业<25km）采样点。开发并评估了多个区域尺度地质统计学模型，以根据 2008 年至 2014 年 H. physodes 元素浓度的变化，描述大气沉积的广泛变化。经验贝叶斯克里金和共克里金与油砂开采、沥青升级、焦炭材料处理和石灰岩采石场/粉碎影响变量的地衣元素浓度相结合，产生了具有最低验证误差的空间插值估计。为两个全面采样年（2008 年、2014 年）计算了带状分区平均地衣元素浓度，并评估了其时空变化。在靠近主要地表油砂生产作业的中心山谷内，研究区域内每个网格单元的地衣硫浓度都显著增加（44-88%），而单个网格单元的氮浓度略有下降（-20%）。浮尘元素沉积的面积范围通常随着沉积到受增强沉积场外网格限制的地衣的沉积显著增加而增加，反映了新的和不断扩大的地表采矿活动。
