You are here

Big Impacts of Small-Scale Gold Mining in Indonesia

Roughly a gram of gold that a miner will sell to a local trader

by Jenny Goldstein, assistant professor of development sociology, and Tom Pepinsky, associate professor of government

Sitting in a five-seat boat speeding down the Katingan River in Central Kalimantan, Indonesia, we headed toward Telaga, a small fishing village inaccessible by roads, where we planned to conduct exploratory field research on artisanal small-scale gold mining (ASGM). For the remainder of the week, we explored this peat swamp region in our boat, interviewing villagers, meeting with farmers and local officials, touring ecosystem restoration sites, and seeing ASGM activities firsthand.

The story behind this early 2018 trip reflects the interdisciplinary tradition of the Southeast Asia Program. With funding from Cornell’s Atkinson Center for a Sustainable Future, Jenny Goldstein, a geographer and assistant professor in development sociology, and Tom Pepinsky, a political scientist and associate professor in government, joined together to tackle a socio-environmental problem with implications for Indonesia and beyond. Along with Matt Reid, an assistant professor at Cornell’s College of Engineering, we conduct research on the social, political, economic, and environmental dimensions of ASGM.

A core feature of ASGM in Indonesia, as well as throughout Africa and Latin America, is the use of mercury to amalgamate the gold during the mining process. Our project focuses on the human and environmental consequences of mercury use in regions like Central Kalimantan, particularly how mercury use affects miners’ health and how it accumulates in fish consumed by local communities.

This fieldwork has been possible through a partnership with PT Rimba Makmur Utama (PT RMU), an Indonesia-based company that holds an ecosystem restoration concession license for a roughly 150,000-hectare peat swamp forest in Central Kalimantan. Under the leadership of two Cornell alumni, Rezel Kusumaatmadja and Dharsono Hartono, the company has founded the Katingan Mentaya Project, which seeks to conserve and restore the peat forest through community-based sustainable development initiatives.

Peat swamp forests throughout Indonesia store in their soils enormous amounts of carbon, which are released as carbon dioxide if the swamps are deforested and drained for plantation agriculture such as oil palm (the tree crop that produces the ubiquitous palm oil). By helping develop local livelihood activities that keep community members from turning to logging as a source of income, the Katingan Mentaya Project aims to prevent deforestation and maintain the peat soils as a carbon sink. In doing so, they have met the global Verified Carbon Standard criteria to become a carbon offset and have begun to sell carbon credits to international investors. While the mining in the area is outside of the Katingan Mentaya Project site, it nevertheless impacts the watershed and the communities living there. PT RMU provided extensive logistical ground support for our fieldwork and connected us to many community members.

The landscape in regions where ASGM is practiced bears the scars of environmental degradation for years. Miners strip away trees, shrubs, and plants and process the resulting soil through large machines in order to separate out the gold. It can take years for plant life to reappear after gold mining activities have ceased. While ASGM in much of Kalimantan takes place alongside rivers and involves capturing tiny gold particles from water-logged alluvial soils, in other parts of Indonesia ASGM requires digging pits or shafts underground, as gold is also embedded in hard rock. This is a more labor-intensive and dangerous process in which miners also use mercury to capture gold after they use machinery to turn the rock into a slurry.

It is well known that mercury is a dangerous pollutant and poses a toxic risk to human health, particularly to children and pregnant women. Much less understood is how mercury progresses through the environment in places like Central Kalimantan, with carbon-rich peat soils and swamp-based forest ecosystems rich in fish species and wildlife like orangutans. To study this—and to investigate how this mercury enters the food web and its implications for the health of people living in this region—we chose to adopt a holistic approach that traces mercury from the alluvial mining sites in Kalimantan, through the watershed, to the fish people consume as their main protein source. Given that the Indonesian government is party to an international treaty designed to control the use of mercury in ASGM, we are also investigating how this dangerous pollutant is regulated and why this regulation fails to make any dent in mercury use.

Our interests in this project go beyond simple environmental destruction associated with ASGM. A voyage out to sites engaged in current mining activities revealed the stakes for mercury use. After separating out the soil in which gold particles are found, miners combine it with water and mercury to create a slurry. The mercury binds with tiny gold particles to form larger clumps that are easier to sift out of the water. Once the miners have collected this amalgam of gold and mercury from the water and sand, they heat it over an open flame. This causes the mercury to evaporate away, leaving pure gold that the miners can sell to gold traders in regional cities like Sampit and Palangkaraya.

Much like the gold rush in the United States during the nineteenth century, some miners strike it rich. Individuals who stake a claim in mining sites first, and who have been able to form groups with other miners and accumulate some investment capital, earn between $1,000 to $2,000 per month, a huge amount for rural activities in Indonesia. Most miners, however, make far less than that or barely break even, and many give up on ASGM after a few months, if they don’t make much money.

This suggests that some miners might seek other opportunities to make a livelihood that are not so environmentally destructive and hazardous to human health. Part of PT RMU’s work is to help local community members develop new opportunities for income through activities such as agro-forestry, rattan weaving, and edible bird’s nest farming.

Even if local villagers opt to engage in more sustainable (or at least less environmentally destructive) livelihoods, there is a steady supply of migrants from other parts of Indonesia who seek their fortune as small-scale gold miners. This means that we need to understand the broader political and economic systems that make gold mining possible. Mercury is not locally supplied; it is mined from cinnabar on other Indonesian islands, and brokers process it in Java and export it to mining areas. Thus, although Indonesia is a party to the Minamata Convention on Mercury, a global United Nations treaty in which all signatory nations agree to phase out mercury use by 2030, international treaties designed to regulate the cross-border mercury trade have little bite in the context of a purely domestic mercury market.

Returning to what we learned in Central Kalimantan: once the mercury evaporates, it enters the atmosphere. Some amount of it then precipitates down into the water, where it joins any remaining mercury left over from the mining activities. From there, it accumulates in algae, which is eaten by small fish, which, in turn, are eaten by bigger fish. Mercury accumulates most in the fatty tissues of fish species at the top of the food chain, which are frequently consumed by humans. Fish are the main source of protein for these communities, so even if local community members opt not to engage in dangerous mining activities, they have not insulated themselves from the risks of mercury poisoning through fish consumption. Our next phase of research will bring fish samples from these communities to Cornell for laboratory analysis in order to determine how much mercury is in them and, in turn, how much exposure the communities have to the toxin through food consumption. 

Jenny Goldstein Headshot
Tom Pepinsky Headshot
Jenny and Tom
Gold processing pit containing mercury, used to amalgamate the gold.