DISES Investigating mercury biogeochemical cycling via mixed-methods in complex artisanal gold mining landscapes and implications for community health

DISES 通过混合方法研究复杂手工金矿景观中的汞生物地球化学循环及其对社区健康的影响

• 批准号: 2307870
• 负责人: Heidi Hausermann
• 金额: $ 153.77万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2028-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307870&HistoricalAwards=false
• 关键词: DISES; Investigating; mercury; biogeochemical; cycling

Human activities lead to increased contamination in both terrestrial and aquatic ecosystems. Contaminants can pose harm to both people and wildlife, with specific harms and exposures dependent on complex socio-ecological factors. This study investigates environmental risk vis-a-vis mercury (Hg) released from artisanal and small-scale gold mining (ASGM) sites. Mercury is a potent neurotoxin used to amalgamate gold in ASGM contexts globally. ASGM has become the leading cause of mercury emissions worldwide and is particularly harmful when burned off gold and emitted as gaseous elemental mercury (GEM). However, little is known about the fate of mercury from ASGM activities, including if and how mercury accumulates in crops, or local knowledge of mercury dangers and exposure routes, all of which contribute to actual and perceived environmental risk. This research asks: (1) What is the local and regional fate of Hg vaporized from ASGM in terrestrial ecosystems? (2) To what extent is Hg accumulating in crops grown near ASGM, and how do landscape and soil characteristics impact crop Hg concentrations? (3) How do local people understand Hg contamination and exposure, and how do spatialities of local knowledge articulate with environmental contamination variability? Results from this research will provide direct benefits related to the goals of the recently ratified International Minamata Convention on Mercury. The research focuses on mercury in Ghanaian ASGM systems with contrasting geology, mining type, climate, and ecosystem. Ghana possesses extensive ASGM activities, which increased dramatically in the last 15 years. To query the research questions, the researchers employ mixed methods including community mapping activities and semi-structured interviews, biogeochemical data collection (passive air samples, bulk deposition, throughfall, litterfall, soil, and crop) and modeling (empirically constrained mass budgets, Lagrangian plume models). As farmers grow crops directly adjacent to ASGM sites, this project models where mercury travels, and how it accumulates in agricultural fields and specific staple crops grown in both communities (e.g. cassava, cocoa yam, plantain). The data generated from this proposal will improve Hg models, allowing for better understanding of environmental risks and contamination dynamics (i.e., Hg use, atmospheric transport, deposition, soil storage, and crop accumulation) associated with localized ASGM activity. Furthermore, this research systematically investigates what soil and landscape features lead to the accumulation of Hg within crops to better understand potential human exposure pathways to Hg beyond occupational exposure and consumption of contaminated fish. At the end of the project, workshops and training will be organized to inform harm reduction practices, including agricultural and mining practices to reduce mercury accumulation in crops, and other local exposures. This research links together concepts from political ecology and landscape ecology in a dynamic bi-directional coupling of socio-environmental systems that determines where and when contaminants deposit and accumulate on the landscape. The concept of “environmental risk landscape” can be further developed to evaluate environmental risk in other socio-environmental contexts, including environmental injustice in the U.S.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

人类活动导致陆地和水生生态系统的污染增加。污染物可能会对人和野生动植物构成伤害，其特定危害和暴露取决于复杂的社会生态因素。这项研究调查了从手工和小型金矿（ASGM）地点释放的相对于汞（HG）的环境风险。汞是一种潜在的神经毒素，用于在全球ASGM环境中融合金。 ASGM拥有它成为全球汞排放的主要原因，当被燃烧并排放为气态元素汞（GEM）时，尤其有害。但是，对来自ASGM活动的汞命运知之甚少，包括汞在农作物中积累的IF以及如何积累，或当地对汞危险和暴露路线的了解，所有这些都会导致实际和感知到的环境风险。这项研究问：（1）在陆地生态系统中从ASGM蒸发的HG的局部和区域命运是什么？ （2）汞在ASGM附近种植的农作物中积聚在多大程度上，景观和土壤特征如何影响作物HG浓度？ （3）当地人如何了解HG的污染和暴露，以及当地知识的空间如何通过环境污染的变化表达出来？这项研究的结果将提供与最近评级的国际Minamata汞公约的目标有关的直接收益。该研究的重点是与地质，采矿类型，气候和生态系统相比的加纳ASGM系统中的汞。加纳拥有广泛的ASGM活动，在过去的15年中，该活动急剧增加。为了查询研究问题，研究人员的员工混合方法包括社区地图活动和半结构化访谈，生物地球化学数据收集（被动空气样本，批量沉积，遍布，垃圾，垃圾，土壤，土壤和作物）以及建模（经验限制的质量预算，lagrangian梅花模型）。随着农民直接与ASGM地点相邻的农作物，该项目模型的汞在其中旅行，以及该项目如何在农业领域积累，并且在两个社区中种植的特定主食（例如木薯，山药，植物，植物）。该提案产生的数据将改善HG模型，从而更好地了解与局部ASGM活性相关的环境风险和污染动力学（即HG使用，大气传输，沉积，土壤存储和农作物积累）。此外，这项研究系统地研究了哪些土壤和景观特征导致汞在农作物中积累，以更好地了解超出职业暴露和污染鱼类消费的汞的潜在人类暴露途径。在项目结束时，将组织研讨会和培训，以告知减少危害的实践，包括农业和采矿实践，以减少农作物中的汞积累以及其他当地暴露。这项研究将政治生态学和景观生态学的概念联系在一起，与社会环境系统的动态双向耦合，该系统确定了污染物在何时何地沉积和丙烯酸在景观上。可以进一步开发“环境风险格局”的概念，以评估其他社会环境环境中的环境风险，包括美国奖项中的环境伤害反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来评估的支持。