Paleolimnological assessment of the controls on metal mobility in Nova Scotia

新斯科舍省金属流动性控制的古湖泊学评估

• 批准号: RGPIN-2018-05543
• 负责人: Spooner, Ian
• 金额: $ 1.82万
• 依托单位: Acadia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=681028
• 关键词: Paleolimnological; assessment; controls; metal; mobility

Arsenic (As) is a pervasive environmental toxin and carcinogenic metalloid in Maritime Canada. Surface and groundwater systems are highly susceptible to arsenic enrichment. Bioaccumulation of arsenic is a significant concern. In Nova Scotia arsenic poisoning from groundwater sources has been reported and elevated concentrations in soils and aquatic sediments are common. There are many natural local and regional sources of arsenic; mining and development have both concentrated and mobilized the metalloid. The mobility of arsenic among environmental media is complex, the factors affecting the retention and mobility of arsenic in fresh and brackish surface water systems are poorly understood. This research proposal focuses on the use of lake sediment archives (paleolimnology) to better understand how watershed-scale landscape disturbance (mining, development) influences the mobility and retention of arsenic in a variety of environments in Nova Scotia, Canada.*******Research will take place in Halifax Regional Municipality (HRM), Cape Breton Regional Municipality (CBRM) and the Cumberland Marsh Region (Nova Scotia-New Brunswick border region). Stable isotopes (C, N), bulk sediment geochemistry (ICP-MS, XRF, XRD), and a suite of abiotic proxies coupled with radiometric dating (14C and 210Pb) will be applied to lake sediment archives obtained by gravity coring to reconstruct 500-year sedimentary records. Bioproxy research in NS that identified the significant environmental stressors (e.g. pH, T, EH, TP) in surface water systems will be applied to predict how environmental change has and will influence arsenic mobility and retention in lake sediments. Groundwater models are being developed for HRM and CBRM that will be used to help predict the relationship between historical watershed disturbance and the bulk geochemistry of lake sediments. A >300 year historical record of landscape disturbance at all sites will enable the integration of the lake sediment archive with historical records to better understand the relative importance of disturbance, water column chemistry and climate variability on metal mobility and retention. As well, the role of lake sediment composition and lake water column redox conditions in metal sequestration and mobility will be explored.*******This research is collaborative and will be integrated with bioaccumulation and toxicology research already in progress. The proposed research will develop strategies that will facilitate effective watershed management and help determine conditions that increase the risk of elevated arsenic in groundwater and arsenic bioavailability and mobility in aquatic systems. The field and laboratory techniques required in this research will train highly qualified individuals and are transferrable and relatively inexpensive; technology transfer to both the public and private sector will be an important component of this research.***

砷是加拿大海洋地区普遍存在的环境毒素和致癌类金属。地表水和地下水系统对砷富集非常敏感。砷的生物积累是一个重大问题。在新斯科舍省，已有地下水砷中毒的报告，土壤和水生沉积物中砷浓度升高的情况很常见。有许多天然的地方和区域砷来源；采矿和开发既集中又动员了类金属。砷在环境介质中的迁移是复杂的，影响砷在淡水和微咸地表水系统中保留和迁移的因素了解甚少。本研究计划的重点是利用湖泊沉积物档案（古湖泊学）来更好地了解加拿大新斯科舍省各种环境中流域尺度景观干扰（采矿，开发）如何影响砷的迁移和保留。*******研究将在哈利法克斯地区市（HRM）、布雷顿角地区市（CBRM）和坎伯兰沼泽地区（新斯科舍省-新不伦瑞克边境地区）进行。将稳定同位素（C、N）、沉积体地球化学（ICP-MS、XRF、XRD）和一套非生物代用指标结合放射性测年（14C和210Pb），应用于重力取心获得的湖泊沉积物档案，重建500年的沉积记录。生物代理研究确定了地表水系统中重要的环境压力源（如pH、T、EH、TP），将应用于预测环境变化如何影响湖泊沉积物中砷的迁移和滞留。正在开发用于人力资源管理和CBRM的地下水模型，这些模型将用于帮助预测历史流域扰动与湖泊沉积物的总体地球化学之间的关系。对所有地点的景观扰动进行300年的历史记录，将使湖泊沉积物档案与历史记录相结合，从而更好地理解扰动、水柱化学和气候变率对金属迁移和保留的相对重要性。此外，还将探讨湖泊沉积物组成和湖泊水柱氧化还原条件在金属固存和迁移中的作用。*******这项研究是合作的，将与正在进行的生物积累和毒理学研究相结合。拟议的研究将制定战略，促进有效的流域管理，并帮助确定增加地下水中砷含量升高风险的条件，以及水生系统中砷的生物利用度和流动性。这项研究所需的实地和实验室技术将训练出高素质的人员，可转让且相对便宜；向公共和私营部门转让技术将是这项研究的一个重要组成部分