Dr. Bruce Marshall is a Sessional Lecturer at the Norman B. Keevil Institute of Mining Engineering and Research Associate in Chemical and Biological Engineering at UBC, where he is currently setting up a new Mining Micro-biome Laboratory in the Coal and Mineral Processing Laboratory as part of the BRIMM Initiative. The Mining Microbiome is centered upon the idea of using microorganisms to facilitate advances in mineral exploration, increase efficiencies in mineral processing, and to help the efficacy of mitigation strategies aimed at reducing environmental impacts associated with mining activities. Within his own BRIMM research group, Bruce is working to develop a microbial electrolysis cell to precipitate metals leached by acid mine drainage (AMD). The use of exo-electrogenic bacterial strains to remove heavy metals from AMD shows great promise in helping reduce the amount of hydrated lime required to neutralize acidic effluents.
In 2018, Bruce finished a Postdoctoral Fellowship in the Dept. of Mining Engineering with Prof. Dr. Marcello Veiga, where he was part of a team investigating the bioavailability of mercury cyanide in aquatic environments. Mercury cyanide pollution in artisanal and small-scale gold mining is a serious problem in more than 70 countries around the world, as cyanide is increasingly being used to leach residual gold from Hg-contaminated tailings. Bioassay results of fish exposed to high concentrations of mercury cyanide showed bioaccumulation of inorganic mercury into fish tissues and severe kidney failure leading to death. More studies are required to investigate how organics play a role in the toxicity and bioavailability of these complexes in aquatic environments.
In addition to his research, Dr. Marshall has been working as a sessional lecturer at UBC teaching undergraduate and Masters level courses that deal with mining and the environment, mining and society, and environmental risk assessments in relation to mining. In 2016, Dr. Marshall was part of a large UNIDO study investigating heavy metal contamination of the Puyango-Tumbes River in Ecuador in relation to ASGM production in Portovelo-Zaruma, which found that pollution reached the Tumbes Delta in Peru 160 km downriver. In the last five years, Dr. Marshall has also conducted social and environmental risk assessments for three large-scale gold mining companies in Colombia that have been invaded by artisanal miners, whereby a Co-existence model has been promoted to ensure social, environmental and economic sustainability.