Japan's Ashio copper mine
The Ashio copper mine, located about 110 kilometers north of Tokyo, is historically significant, with operations beginning in the seventeenth century and private ownership leading to major development in 1877. By 1890, it had become the largest copper mine in Asia, with production peaking during the Korean War in the 1950s. However, the mine's operations resulted in severe environmental consequences, particularly affecting the nearby Watarase River. Pollution from waste products led to the decimation of fish populations and significant health issues for local communities reliant on the river for food. Deforestation for mine operations exacerbated flooding, damaging agricultural lands and rendering the soil toxic with heavy metals and other contaminants. Despite government intervention and pollution-control measures, the ecological damage persisted, leading to the mine's closure in 1972. By that time, extensive contamination had caused serious economic and health repercussions for local residents, including high infant mortality rates and chronic health issues. Efforts to rehabilitate the area have largely been unsuccessful, leaving a complex legacy of industrial impact on the environment and local livelihoods.
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Japan's Ashio copper mine
Identification: Copper mine that operated at the headwaters of the Watarase River from the seventeenth century to 1972
Development of the Ashio copper mine propelled Japan’s industrial revolution and also set the stage for the nation’s first conflict over environmental quality. Hazardous runoff from the mine caused tension between agriculture and industry and dramatized the human and environmental costs of industrial pollution.
The Ashio copper mine, located 110 kilometers (68 miles) north of Tokyo, first operated during the seventeenth century, but private ownership spurred development of the mine in 1877. By 1890, it was the largest copper mine in Asia. Production expanded in 1950 because of the Korean War.
As copper production increased, the Ashio mine’s impacts on the surrounding area also increased. Located at the headwaters of the Watarase River, the mine caused environmental damage by depositing waste products in the river. By 1880 fish were beginning to die, and people who ate fish from the river became ill. Almost all marine life in the river had died by 1890. Deforestation compounded the pollution problem. The operation of the mine required timber to shore up the mine shafts, for railroad ties, for the construction of buildings, and as fuel for steam engines. This timber was obtained through the deforestation of 104 square kilometers (40 square miles) of surrounding land, which destroyed the watershed at the head of the Watarase River. As a consequence, flooding became a serious problem in the Watarase Valley and the surrounding rice fields.
Although natural flooding had occurred before the development of the mine, such flooding had brought layers of rich silt that contributed to abundant crops. Later floods, however, produced vastly different results: Vegetation did not survive contact with the contaminated floodwaters. Floods became more frequent, more severe, and more damaging because they left poisons in the soil. Soil samples revealed concentrations of sulfuric acid, ammonia, magnesium, iron, arsenic, copper, and chlorine. These substances poisoned the rice fields, and new seeds would not grow. Earthworms, insects, birds, and animals succumbed to the contamination.
Although the Japanese government ordered pollution-control measures, they were ineffective. In 1907 the government forced the evacuation and relocation of the inhabitants of a contaminated village. The collapse of a slag pile in 1958 introduced 2,000 cubic meters (71,000 cubic feet) of slag into the Watarase River, contaminating 6,000 hectares (14,820 acres) of rice fields. The Japanese government set limits on the amount of copper that could be deposited in the river water and the soil, but the damage had already been done. In 1972 the mine was shut down. That year, soil samples from 3 meters (9.8 feet) down still contained excessive amounts of copper as well as significant amounts of lead, zinc, and arsenic. The government ordered the destruction of all rice that had been grown in the area.
Thousands of fishermen, rice farmers, and valley citizens suffered severe economic losses. Serious health problems in the area included a high infant mortality rate, the failure of new mothers to produce milk for their infants, sores on those who worked in the fields, and a high death rate. In 1973 the Japanese Environmental Agency’s Pollution Adjustment Committee began to review farmers’ claims. The mine was required to admit to being the source of the contamination, and the farmers were awarded a sum equivalent to five million U.S. dollars in 1974. Attempts to reforest the area have failed.
Bibliography
Tsuru, Shigeto. The Political Economy of the Environment: The Case of Japan. Vancouver: University of British Columbia Press, 1999.
Wilkening, Kenneth E. Acid Rain Science and Politics in Japan: A History of Knowledge and Action Toward Sustainability. Cambridge, Mass.: MIT Press, 2004.