Placer mining significantly impacts the environment by altering hydrological regimes and geomorphology, leading to increased sediment loading, turbidity, and physical changes to riverbeds and channels (USGS, 1981).
Water quality degrades due to chemical contamination from heavy metals like arsenic, potential acid mine drainage (AMD), organic loading, and thermal pollution (USGS, 1997).
Aquatic ecosystems suffer from habitat destruction, loss of riparian zones, and direct harm to fish and benthic invertebrates. Fish populations decline due to sediment, chemical toxicity, and migration barriers (Wildsight, 2017).
Terrestrial impacts include soil erosion, topsoil loss, landscape scarring, and destruction of vegetation and wildlife habitats (Ecological Improvements, 2023).
Mercury pollution, especially from artisanal and small-scale gold mining (ASGM), is a critical concern, releasing mercury into air, water, and soil, leading to bioaccumulation and severe health risks for miners and communities (Jaishankar et al., 2018).
Different mining techniques have varying impact intensities, but all can cause long-term and cumulative environmental damage (USGS, 1999). Effective mitigation, reclamation, and robust regulatory frameworks are crucial to address these impacts (Jouav, 2024).
Which environmental impact of placer mining do you think is the hardest to reverse: water pollution, habitat destruction, or mercury contamination? Share your thoughts!
References:
Ecological Improvements (2023). Erosion and Human Activities: Examining the Role of Mining. Retrieved from https://www.ecologicalimprovements.com/blog/erosion-and-human-activities-examining-the-role-of-mining
Jaishankar, M., Tseten, T., Anbalagan, N., Mathew, B. B., & Beeregowda, K. N. (2018). Toxicity, mechanism and health effects of some heavy metals. Interdisciplinary1 Toxicology, 7(2), 60-72. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC5969110/
Jouav (2024). Mine Reclamation: A Comprehensive Guide to Restoring Mined Land. Retrieved from https://www.jouav.com/blog/mine-reclamation.html
USGS (United States Geological Survey) (1981). Effects of Placer Mining on Hydrologic Systems in Alaska – Status of Knowledge. Retrieved from https://dggs.alaska.gov/webpubs/outside/text/blm_tr_07.pdf
USGS (United States Geological Survey) (1997). Environmental Geochemistry of the Fortymile River System, East-Central Alaska. Retrieved from https://pubs.usgs.gov/fs/fs-0155-97/fs-0155-97.pdf
USGS (United States Geological Survey) (1999). Environmental Geochemistry of the Fortymile River System, East-Central Alaska — An Example of the Effects of Placer Gold Mining. Retrieved from https://pubs.usgs.gov/of/1999/0328/report.pdf
Wildsight (2017). High Environmental Impacts vs. Low Economic Return of B.C. Placer Mining. Retrieved from(https://wildsight.ca/wp-content/uploads/2017/04/BCPlacer_Environment_Economic.pdf)
