CISITU, Indonesia — In the remote mountains of West Java, workers like 15-year-old David Mario Chandra are an integral part of Indonesia’s gold industry. A workshop next to his family’s house in Cisitu, in Banten Province, contains machinery that turns gold ore into usable nuggets. The procedure seems simple enough: The crushed ore is tumbled with other ingredients in cylinders called balls until the valuable stuff is amalgamated. But there is a crucial material — and a final step — that alarms environmental and health experts around the world.
“We put 15 kilograms of gold ore and water into each ball, and we use 100 grams of mercury per ball,” or 3.5 ounces for 33 pounds of ore, said David, who runs the family’s workshop. Workers then purify the nuggets using an open flame, burning off the mercury in sites among residential areas throughout the village.
Yuyun Ismawati, an environmental campaigner based in Britain, says the scope of the problem is evident in the amount of mercury being exported from around the world to Indonesia, her home country. Most of it, she says, is brought in illegally.
According to the Indonesian Ministry of Trade, the country imported slightly less than one metric ton of mercury in 2012 through two local companies, primarily for commercial manufacturing, including the production of light bulbs and batteries, and for use in hospital equipment. According to United Nations trade statistics, however, 368 metric tons of mercury, about 810,000 pounds, were legally exported to Indonesia in 2012 from countries that included Singapore, the United States, Japan and Thailand.
The yawning gap between what Indonesia officially reported as receiving and what was actually exported to it is not an anomaly. In 2011, the country officially imported 7.8 metric tons of mercury, while the United Nations reported that 286 metric tons was exported to Indonesia. The same disparity is evident for numerous other recent years.
In fact, the only data that added up for Ms. Yuyun, 49, a graduate school alumna of Oxford, was not about mercury but global gold prices, which nearly doubled from an average of $872 an ounce in 2008 to $1,669 in 2012. Gold ended 2013 at just over $1,200 an ounce.
To Ms. Yuyun, the conclusion was obvious: Hundreds of tons of mercury had been smuggled into Indonesia for illegal, small-scale miners in a modern gold rush that analysts and activists say is causing major environmental and health crises.
“It’s quick cash,” she said. “You dig, you get money — and you get poisoned.”
The quick and dirty production process emits mercury into the atmosphere. The metal has also seeped into soil, rivers, fish ponds and rice fields. Mercury is known to cause health problems, which may not appear for years, that include brain damage; kidney, skin and eye problems; miscarriages; and dysfunctional neurological development in infants and children.
Then there are the environmental impacts. According to the United Nations Environment Program, small-scale gold mining is responsible for 37 percent of global mercury emissions and is the largest source of air and water mercury pollution.
According to a study by the Blacksmith Institute, a nonprofit research organization in New York that focuses on pollution, one-tenth of global mercury emissions from such mining originate in Indonesia. Those emissions can spread from country to country and continent to continent.
Parts of Indonesia, including the resort island of Lombok, where illegal gold mining is rampant, have the highest mercury contamination readings on earth, according to studies by Blacksmith and other groups.
Industrial gold mining companies in Indonesia are forbidden to use mercury during processing, government officials said. They would not anyway, as they can afford safer, more effective alternatives. But the country does not ban mercury use outright in small-scale gold mining operations.