Aquatic mercury pollution from artisanal and small-scale gold mining in Sub-Saharan Africa : status, impacts, and interventions

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Authors

Mulenga, Mary
Ouma, Kennedy O.
Monde, Concillia
Syampungani, Stephen

Journal Title

Journal ISSN

Volume Title

Publisher

MDPI

Abstract

Mercury (Hg) pollution remains an environmental global concern due to its non-degradable and toxic nature. Natural and anthropogenic sources of Hg adversely affect the functioning of aquatic ecosystems and biological processes. In sub-Saharan Africa (SSA), unregulated artisanal and small-scale gold mining (ASGM) contributes up to 20% of global gold production and uses 205–496 tonnes/yr of Hg. Despite being a vital economic driver for 20–30 million people, ASGM threatens the health of aquatic systems from Hg pollution, presenting a complex challenge that demands urgent interventions. This review seeks to (1) establish the current status of aquatic Hg pollution, (2) explore the environmental impacts of aquatic Hg, and (3) highlight the proposed interventions for aquatic Hg pollution in SSA. We examined publications and institutional reports between 2000 and 2023 addressing aquatic Hg pollution, impacts, and interventions in the ASGM of SSA. Results indicate a rise in aquatic Hg pollution due to the expansion and intensification of ASGM. West Africa remained the highest contributor (50.2%), followed by Central Africa (39.6%), Southern Africa (9.6%), and Eastern Africa (<1%). Contamination of freshwater ecosystems, toxicity to aquatic biota, and environmental health risks to humans were evident. Alternative Hg-free ASGM technologies, including physical, metallurgical, and pyrometallurgical, were investigated from case studies and recommended for adoption.

Description

DATA AVAILABILITY STATEMENT : Publicly available datasets were analysed in this review. The main datasets can be found here: [https://minamataconvention.org/en/parties/minamata-initial-assessments; https://minamataconvention.org; https://wedocs.unep.org/handle/20.500.11822/29830). More supporting data sources are available in the literature cited in this review.

Keywords

Mercury (Hg), Pollution, Aquatic mercury pollution, Minamata Convention, Mercury-free technologies, Artisanal and small-scale mining (ASGM), Sub-Saharan Africa (SSA), Global mercury assessment (GMA), Minamata initial assessment (MIA), SDG-09: Industry, innovation and infrastructure

Sustainable Development Goals

SDG-09: Industry, innovation and infrastructure

Citation

Mulenga, M.; Ouma, K.O.; Monde, C.; Syampungani, S. Aquatic Mercury Pollution from Artisanal and Small-Scale Gold Mining in Sub-Saharan Africa: Status, Impacts, and Interventions. Water 2024, 16, 756. https://doi.org/10.3390/w16050756.