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There is a variety of health and environmental issues associated with artisanal and small-scale gold mining (ASGM), which includes concerns regarding mercury pollution. In many countries, intervention programs and policies emphasized the importance of reducing mercury use by focusing on viable alternative methods to amalgamation that may include a transition to cyanidation. ASGM communities that now employ a combination of both methods may be increasing health and environmental risks by using mercury-contaminated tailings in the cyanidation process. This review provides a current overview of mercury and cyanide use in ASGM including the dangers of centralized processing centers that lack best practices. The combination of amalgamation and cyanidation has the potential to adversely affect many ASGM communities around the world and necessitates additional investigations to determine environmental and health impacts.

Naturally occurring anthocyanin indicators have been used for many years to introduce science students to acid–base concepts. A classroom activity has been developed that uses naturally occurring anthocyanins to monitor the pH changes associated with the fermentation of red cabbage to sauerkraut by lactic acid bacteria. Through the activity and related discussion, students are introduced to the scientific method, basic laboratory practices, acid–base chemistry, chemical and physical changes, fermentation, and microbiology. Although this activity and accompanying assignments are designed for students ages 6–12, the activity is adaptable to students of all ages and backgrounds.

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Artisanal and small-scale gold mining (ASGM) is recognized as the number one source of anthropogenic mercury pollution in the world. Miners use mercury to amalgamate gold, then heat the amalgam to evaporate the mercury. This process, referred to by miners as burning, releases large quantities of mercury vapor that affects the health of miners and community members. A retort is a mercury capture device that provides a simple solution to reduce human exposure to mercury vapor during the burning process. In spite of the low cost, ease of use and numerous outreach programs that have introduced miners to this technology, miners have been reluctant to use retorts. This chapter provides a review of ASGM processes involving mercury, discusses the health effects of mercury vapor, and provides case studies on retort use in Mozambique, Ecuador and Guyana. The chapter concludes with a discussion on reasons why retorts have not been widely adopted in these countries, and it provides potential solutions to address miners concerns with the use of retorts.

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A three-phase, 11-day training program designed to monitor elemental mercury (Hg0) emissions originating from gold shops was conducted in Georgetown and Bartica, Guyana, during May of 2019. The first phase consisted of interactive lectures and discussions on mercury use in artisanal and small-scale gold mining throughout Guyana, the region, and the world. In addition, specific training in the theory and use of analytical instrumentation to quantify Hg0 pollution associated with the processing of amalgams and sponge gold occurred. Trainees participated in the mapping of smelting facilities in Georgetown where, outside of one gold shop, Hg0 concentrations exceeded 100,000 ng/m3. During the second phase of training, a subset of trainees traveled to Bartica, where they mapped the town center to identify point sources of Hg0 pollution, all of which corresponded to the location of shops where amalgams and sponge gold were heated and purchased. Once mapped, Hg0 concentrations were measured during the smelting of gold inside the Guyana Gold Board (GGB) facility and two privately-owned gold shops. Maximum Hg0 concentrations at the GGB facility did not exceed 98,700 ng/m3 during the measurement period, while maximum concentrations at the two privately owned shops were measured as 527,500 ng/m3 and 302,200 ng/m3. With guidance from the training team, trainees were responsible for the collection and interpretation of all data. The third phase of the training involved the collaborative production of a report summarizing the findings from the training. This work represents the first formal training opportunity for the assessment of Hg0 concentrations in and around gold shops in Guyana, and provides baseline data to assist the government of Guyana to generate air quality standards for Hg0 emissions.