Field Testing a Mercury Capture System for Artisanal Gold Mining (2021-2022)


Mercury (Hg) is a pollutant that adversely affects human and environmental health around the world. The World Health Organization classifies it as one of the top ten most important chemicals of public health concern. 

Artisanal and small-scale gold mining is the world’s largest contributor of anthropogenic atmospheric mercury and one of the largest threats to forests and biodiversity in the Amazon. Liquid elemental mercury (Hg0) is added to excavated ground soil to bind with gold particles in the soil matrix, forming an amalgam. Burning the amalgam removes mercury, leaving purified gold, yet much of the mercury is lost to the atmosphere or to contaminated waste soils near the excavation site. 

Mercury eventually enters aquatic watersheds via erosion or atmospheric deposition where the Hg0 is converted into monomethyl mercury (MeHg). Parties to the Global Mercury Treaty are committed to implementing programs to reduce mercury pollution and improve human and environmental health. Scientists are starting to develop and test low-cost technologies that can be adopted by miners to reduce mercury release. 

Project Description

An international team including Duke faculty received the top prize in the Artisanal Mining Grand Challenge for its Mercury Capture System (MCS), which has been tested under laboratory conditions. The next step is to test it in field conditions. 

The goal of this project is to design a trial to test the multidimensional efficacy of the MCS and its societal adoptability in one of the partner field sites (Peru, Colombia, Ecuador, Guyana). The project team will identify technical requirements, economic drivers and policy needs. 

Team members will compare gold shops with MCS instruments to those without them. Within that setting, initial trials will document most narrowly the change in airborne mercury within the shop. They will also examine flows of mercury into the local air and beyond. Since an ultimate goal is improvements in human health, team members will track exposures and mercury deposition and bioaccumulation, such as changes in nearby forest canopies, bioaccumulation in fish, and ingestion and exposure in local wildlife.

The team will evaluate the decision-making process for technology adoption by studying miners’ choices to bring mercury-gold amalgams to these shops, as well as motivations. Team members will also evaluate the economic drivers of technology adoption. This analysis will include an examination of actors in the supply chain; for example, consumers may view gold processed by an MCS as a different product – a form of “greener gold.”

Learn more about this project team by viewing the team's video.

Anticipated Outputs

Peer-reviewed manuscripts; policy recommendations; funding proposals; MCS webpage

Student Opportunities

Ideally, this project team will include 3 graduate students and 3 undergraduate students.

A doctoral student interested in including the development and implementation of the MCS trial as part of their dissertation is encouraged to apply. This student may be from any scientific background but should be willing to learn fundamentals of randomized control trials, environmental toxicology (focusing on mercury) and mercury biogeochemical cycling. Undergraduate students should be interested in environmental science, global health, policy, economics and/or engineering. 

Students should actively engage in all aspects of project development and execution. This project will be implemented in Latin America; therefore, knowledge of Spanish will be helpful, but it is not required. In addition, students with experience working or living overseas will also be helpful, but not required. 

Students will have the opportunity to engage in interdisciplinary research and learn specific skills regarding study design, mercury toxicity and cycling, economic evaluation and behavioral aspects of technology adoption. While the entire team will be involved in designing the trials to test the current MCS prototype, this technology may require contextual modifications, culturally appropriate incentives or other changes ideal for both undergraduate and graduate students to consider for pilot testing in various locations. This team provides an ideal environment for learning specific skill sets, yet allowing input for new, creative ideas from students.

This team will meet weekly and conduct open communication with partners outside of Duke. Timelines and expectations will be developed once the team is formed.

A graduate student will be selected to serve as project manager.

Selected students will have the opportunity to travel (depending on COVID-19 guidelines). The optional summer component will take place in May-August 2021. Team leaders expect a minimum of half-time support but would encourage full-time work.


Summer 2021 – Summer 2022

  • Summer 2021 (optional): Review MCS application to Artisanal Mining Challenge; meet with external MCS Scientific Team; create logic model for MCS evaluation; create list of potential funders to support pilot and large-scale field trials
  • Fall 2021: Complete MCS field trial protocol; coordinate with partner sites; finish grant applications
  • Spring 2022: Assist in implementation of randomized trial with MCS Scientific Team at selected site
  • Summer 2022 (optional): Continue collaboration with MCS Scientific Team; field work


Academic credit available for fall and spring semesters; summer funding available


Image: Gold mining along the Madre de Dios River in Peru, courtesy of Jackie Gerson

Gold mining along the Madre de Dios River in Peru.

Team Leaders

  • Heileen Hsu-Kim, Pratt School of Engineering-Civil & Environmental Engineering
  • William Pan, Nicholas School of the Environment-Environmental Sciences and Policy
  • Alexander Pfaff, Sanford School of Public Policy

/graduate Team Members

  • Axel Berky, Environment-PHD
  • Reshma Nargund, Environment-PHD

/zcommunity Team Members

  • Mercury Capture System Science Team - Mercer University
  • Peru Ministry of Health
  • Peru Ministry of the Environment
  • Instituto de Investigaciones de la Amazonia Peruana (IIAP)
  • Asociacion para la Conservacion de la Cuenca Amazonica
  • Uni-Andes, Colombia