Presentation Information
[3K0501-03-03]Hydro-environmental Assessment of Mercury Migration in a Watershed Influenced by Artisanal Small-Scale Gold Mining (ASGM) in Paracale Mineral District, Philippines
○Aeron Elvin Chavez Dela Cruz1[Student presentation: Master’s course], Takahiko Arima1, Tetsuo Yasutaka2, Tum Sereyroith2, Miu Nishikata2, Yuka Sayama2, Hajime Iwaki1, Naoki Hiroyoshi1 (1. Hokkaido University, 2. National Institute of Advanced Industrial Science and Technology)
Chairperson: ジョン サンヒ（秋田大学）、パク イルファン（北海道大学）
Keywords:
Artisanal Small-Scale Gold Mining,Mercury Amalgamation,Geochemical
Artisanal Small-Scale Gold Mining (ASGM) is a widespread mining activity conducted by individuals or small associations with limited capital investment and low production capacity, commonly relying on mercury amalgamation to extract gold from ore. While ASGM provides an important source of livelihood in many developing countries, informal and poorly regulated operations often result in environmental degradation and human health risks, particularly across South America, Africa, and Southeast Asia. Mercury released during ASGM is highly toxic and persistent, accumulating in soils, sediments, and surface and groundwater systems.The Philippines, recognized for its rich metallic mineral resources, hosts numerous small-scale gold mining operations, with around twenty provinces reportedly continuing the use of mercury in ASGM practices. This study focuses on the Magsimalo Watershed within the Paracale Mineral District in southeastern Luzon Island, adopting a watershed-based approach to evaluate mercury transport and behavior.The study area is characterized by complex geology associated with an intrusive granodiorite body that enhances mineralization, including sulfide ores, quartz veins, and clay-oxide alteration zones typical of vein-type gold deposits. Vein-type mining in the area involves ore crushing followed by mercury application for gold recovery, increasing contamination potential. The objectives of this study are to characterize hydro-environmental conditions controlling contaminant transport, assess water quality through physicochemical analyses, and develop management strategies by delineating mercury contamination zones in ASGM-affected areas. The methodology includes hydro-environmental mapping, in situ measurements, interviews, and collection of water, soil, sediment, and tailings samples. Laboratory analyses will quantify total mercury concentrations and other geochemical parameters, while data interpretation will employ geochemical diagrams and conceptual modeling. The resulting conceptual model will elucidate mercury contamination pathways within ASGM-impacted watershed tributaries and support mitigation strategies applicable in the Philippines and other countries facing ASGM-related water pollution challenges.