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Chapter - 1 The Ashio Copper mine pollution case: The origins of environmental destruction

I. Technological modernization and the Ashio Copper Mine
II. Protests against mining poisons and governmental measures
III. Mine operations in the Post Sino-Japanese War era and the stance of the government
IV. Tanaka's attempt to appeal directly to the emperor and the poisoned water-collection pond plan
V. Shozo Tanaka takes up residence in Yanaka village
VI. The historical implications of the Ashio Copper-mine poisoning incidents
VII. Copper-poisoning issues and their aftermath
VIII. Conclusions: Lessons for today from the Ashio Copper-mine poisonings

Kichiro Shoji and Masuro Sugai

I. Technological modernization and the Ashio Copper Mine

In 1868, the newly established Meiji government of Japan made the modernization of the country by increasing military strength and expanding industrial production its first national priority. The government established a Department of Industry in 1870 and came to control all industries other than the military. On the basis of land taxes, this new department took the initiative in starting new industries, and looking after private enterprise until the department was disbanded in 1885. The work that the department had done was to introduce new technologies and machines from the advanced capitalist countries and also to invite technicians to Japan to provide new industrial production models and technologies.

Related industrial laws were established and, by 1877, mining, financed by private capital, had grown rapidly. Copper was especially important for the new government, because its exports brought in much-needed foreign money. The demand for copper overseas supported the copper industry in Japan. As table 1.1 indicates, most of the copper produced in Japan was exported. Copper earned 9.5 per cent of Japan's export earnings in 1890 and through this Japan became established as a world-level copper producer. The earnings were used to purchase mining equipment, military weapons, and other industrial machinery. Copper played an important role in the development of Japan's capitalism, and the main domestic copper producer was the Ashio copper mine.

The Ashio copper mine had been the property of the Tokugawa shogunate, and as such had produced 1,500 tons annually, which was the maximum possible output in the 1600s. However, this high output level had been dropping gradually. The mine was temporarily closed in 1800, but in 1871 it became a private operation, and finally in 1877 it came to be owned by Ichibei Furukawa. In 1881 a new but small lode of ore was discovered, followed by a much larger one in 1884, and, as indicated in table 1.2, copper production rose very rapidly as a result of these discoveries. In 1884, the production stood at 2,286 tons per year. Thus Ashio became the mine with the highest output in Japan, producing 68 per cent of the total output of Furukawa mines and 26 per cent of Japan's production.

Table 1.1. Copper Export as a Percentage of Production


Export/production (%)

1882 49.4
1884 59.3
1886 100.4
1888 72.4
1890 107.6
1892 87.4
1894 76.9
1896 72.6
1898 79.3
1900 82.0

Source: Nihon Keieishi Kenkyuujo, Furukawa Kogyo sogyo 100 nenshi (Furukawa Kogyo, 1976). p. 73.

From 1876 to 1885, the demand for copper was rather low, because mining technology in Western countries was on the upswing and because the world's copper market had fallen into a depression. This also had an effect on Japan's copper production which, in like manner, faced marketing difficulties during that period. In spite of its primitive methods and the depression in the world's copper markets, the Ashio mine was prosperous because of the excellent quality of the ore discovered in the larger lode.

In 1885, Furukawa bought the Ani mine from the government, not only to add another productive mine to the company's holdings, but also to provide an opportunity to make use of the latest modern equipment that had been installed there, as well as its highly skilled technicians. This equipment from the Ani mine enabled the Ashio mine to modernize the system for pumping the water and ore slurry, which up until then had been done manually, because the newer ore-digging and crushing equipment incorporated a steam-operated pumping method. With the help of foreign technicians the mine was reorganized for more efficient output on the basis of new techniques and equipment, and the horizontal mining method was introduced. However, the mine's capital accumulation was as yet insufficient for the further introduction of advanced production technologies.

In September 1885 when the Ashio mine was flooded, the technical limitations were revealed. Although production had reached a record 4,090 tons that year, it took another two years before the former production levels were regained. The years 1886-1887 saw a depression in world copper markets. The Jardine Matheson Company, the largest of all British companies in South-East Asia at that time, requested exclusive purchasing rights for all Furukawa's copper output. with the aim of creating a monopoly in world markets and forcing an increase in the price of French-produced copper.

Table 1.2.


Production (tons)



Ashio mine

Furukawa mine (a)

All Japan (b)


1874     2,111  
1875     2,399  
1876     3,181  
1877 46 149 3,943 3.8
1878 48 158 4,256 3.7
1879 90 263 4,630 5.7
1980 91 268 4,669 5.7
1881 172 370 4,669 7.9
1882 132 737 5,616 13.1
1883 647 1,671 6,775 24.7
1884 2.286 3,411 8,888 38.4
1885 4,090 5,250 10,541 49.8
1886 3.595 5.100 9,774 52.2
1887 2,987 4,455 11,064 40.3
1888 3.783 4.180 13,255 31.5
1889 4.839 5,999 16,254 36.9
1890 5.789 7.589 18,115 41.9
1891 7,547 7.681 19,003 40.4
1892 6,468 7,397 20,727 35.7
1893 5,165 6,928 18,015 38.5
1894 5.877 8.017 19,912 40.3
1895 4.898 6,587 19,114 34.5
1896 5.861 7.695 20,102 38.3
1897 5.298 7,964 20,389 39.1
1898 5.443 8.764 21.024 41.7
1899 5.763 9,191 24,276 31.9
1900 6.077 8,924 24,317 36.7
1901 6,320 9.089 27,392 33.2
1902 6.695 8.194 29,035 28.2
1903 6.855 9,290 33,187 28.0
1904 6.520 8.986 32,123 28.0
1905 6.577 8.949 35,495 25.2
1906 6.735 9.580 37,432 25.6
1907 6.349 9.298 38,714 24.0

Source: Nihon Keieishi Kenkyuujo. Furukawa Kogyo sogyo 100 nenshi (Furukawa Kogyo. 1976), pp. 76. 82.

At first Furukawa was unwilling to conclude this contract because of the large amount of copper to be sold and the terms of the payment. But in 1888 a contract was signed: Furukawa was to sell 19,000 tons of copper at the Yokohama rate of 20.75 yen per 100 kin (I kin = 0.6 kg) for 29 months. With this contract in hand, Furukawa could make capital borrowings, but in order to realize these the output of the Ashio mine had to be greatly increased.

Under these conditions it was not only essential but inevitable that the technology used in the Ashio copper mine be updated and modernized. The problem of flooding, which had plagued the mine for three years, was solved within the year. Furukawa was the first to install a telephone system in the mine. Various kinds of mining equipment were imported for drainage and the transportation of ores' and the production was generally improved. Further, the company initiated innovations that were to increase production capacity, reduce the need for labour, and cut the cost of production.

However, no matter how much effort was given to increasing copper production, the refining method was still rather primitive. In 1887, of the 48 refining sites, eight were abolished and replaced by one modern hydrometallurgical separator and three pyrometallurgical smelters. In 1890, in order to meet the contract demands of the Jardine Matheson Company, another 12 hydrometallurgical separators were installed to replace the old smelters.

There were many problems like excessive energy consumption and product and ore transportation. In 1890, Furukawa requested the Siemens Company of Germany to install a 400-horsepower hydro-electric turbine that was to run an electric generator to power an 80-horsepower pump, a 25-horsepower ore lift, and a 6-horsepower electric-light system. The electric pump was of the plunger type which provided greater efficiency and energy conservation in water drainage and ore transportation. In 1891 an electric railway was built between the mine and the refining area.

Because the transportation of the finished products was dependent on the use of horses and cows, weather and temperature caused problems. In order to solve them, the company installed a 30-horsepower steam-engine-powered cable across the Hosoo Pass in 1890. Then, when the Japan National Railway opened the Nikko rail line, the company began to operate a horse-drawn train between the Hosoo Pass and Nikko, thereby greatly improving the product transportation system.

In 1893 Furukawa built a Bessemer smelter. With the help of this, the time needed for the refining of the ore was reduced from 32 to 2 days. The Ashio copper mine now became the leading copper producer as a result of its greatly increased productivity.

II. Protests against mining poisons and governmental measures

The predominantly capitalistic production system of the Ashio copper mine brought about serious mining-induced environmental destruction. As indicated in figure 1.1, the discovery of the large copper ore lode caused all the trees surrounding it to die by the end of 1884. In August 1885. the use of a rock-crushing machine and a steam-operated pump in the Ani mine greatly increased production but led to massive fish kills in the Watarase River. In

Fig. 1.1. Process of Environmental Destruction around Ashio Copper Mine (after K. Shoji, production figures from Furukawa Kogyo sogyo 100 nenshi, p. 82).

August 1890, when all modern technology systems had been installed, £1 flood occurred in the Watarase river basin, and 1,600 hectares of farmland and 28 towns and villages in Tochigi and Gunma prefectures were heavily damaged by the floodwater, which contained poisons from the Ashio mine.

In October 1890, Chugo Hayakawa led a movement against the mine and asked the prefectural hospital to do some tests for water-borne poisons. In December, the residents of Azuma Village, Tochigi Prefecture, appealed to the governor of the prefecture to call a halt to the mining operations at Ashio. This was the first of such appeals and of the movements against Ashio.

In December 1890, the Tochigi Prefectural Council resolved that the poison problems should be investigated. Gunma Prefecture followed their lead in March 1891. In April 1891, the governor of Tochigi made a request to the Agricultural University to investigate the causes of the damage to agricultural systems, and asked for countermeasures. He was followed by the governor of Gunma, who did the same in June and July. During these periods the farmers began to organize their efforts to counteract the mining poisons. Sukeyuki Cho, Chugo Hayakawa, and Sahei Kameda from the Ashikaga and Yamada areas of Tochigi formed volunteer groups, and started to organize the provinces of Yamada, Nitta, and Oura in Gunma Prefecture in order to stop the mining. At the same time they published the results of soil analysis and other surveys related to the Ashio mine poisons. carried out by Professor Yoshinao Kozai of the Agricultural University, but the book was immediately confiscated by the authorities.

The destruction of agricultural ecosystems by the Ashio water-borne poisons provoked a response from the farmers, which at first was oriented towards stopping the operation of the mine altogether, but which was also concerned with gaining monetary compensation from the mine-owners for the extensive damage that had been done. In September 1891, the governor of Tochigi Prefecture proposed to lay the groundwork for negotiations between the farmers and the Furukawa management concerning possible compensation for damages on condition that the former agreed to mediation through the governor. The representatives of six villages in the Ashikaga area and three in the Yamada area, including Sahei Kameda of Azuma Village, agreed to accept the proposal. In this way the farmers' movement against the operations of the copper mines slowly changed into a movement to demand compensation for damage. Japanese governmental attitudes toward the Ashio copper mine problems and measures to resolve them were reflected in the Imperial Constitution of Japan, which was promulgated in February 1889.

Prima facie the Imperial Constitution was egalitarian, but in reality the rights of the people and the Imperial Diet were tightly circumscribed in deference to the authority of the Emperor, who, as the sovereign head of state and commander-in-chief of the armed forces, retained the power to declare war and negotiate peace. The National Diet was not able to interfere in military affairs, and its deliberation of budget bills was also limited. The power to form or disband governmental organizations belonged exclusively to the Emperor.

The concentration of power in the hands of the Emperor inevitably created advisory organs like Genro, which were exclusively manned by members of the Satsuma and Choshu clans, who had been instrumental in bringing about the Meiji Restoration and in establishing the bureaucratic system of Japan.

Elections were held only for members of the Lower House of the Imperial Diet, which was established in November 1890, while the Upper House was constituted through Imperial Orders and consisted of noblemen, bureaucrats, large landowners, and industrial capitalists. This system of government was established under the Emperor in collusion with large landowners and industrial capitalists who had accumulated their wealth by taking advantage of the Matsukata Monetary Retrenchment Measures instituted in 1881. It was this same group that had established the Department of Industry within the government.

With this amount of power concentrated through governmental structures in the hands of a few individuals, policies were oriented toward strengthening military power and the creation of a technologically sophisticated industrial state. In this context and under the Imperial Constitution, the political and economic roles of the Ashio copper mine were strengthened, because copper was an important foreign money-earner, and foreign money was needed for the purchase and importation of weapons and industrial machinery. Against this background, Ichibei Furukawa succeeded in establishing solid relationships with those in governmental circles.

Furukawa continued his relationship with Eiichi Shibusawa, the leading capitalist of the times, and he was greatly supported by Kaoru Inoue, a political magnate who had served the Foreign Ministry and the Department of Industry. Junkichi, the second son of the future Foreign Minister Munemitsu Mutsu, was adopted as a son-in-law by Ichibei Furukawa and through this the ties between the two families were cemented, which did much to strengthen their economic and political power. In 1890, Mutsu was appointed to the Ministry of Agriculture and Business, and Mutsu's secretary, Takashi Hara, became vice-president of Furukawa Mining in 1905. In 1907, Hara became the Minister of Home Affairs, and ordered the destruction of Yanaka Village. Hara's talent had first been recognized by Kaoru Inoue, the then Minister of Foreign Affairs, and this led to his becoming a foreign affairs appointee to France. While Hara was in France. he had become acquainted with Tsugumitsu Saigo of the Japanese Navy, and Aritomo Yamagata of the Japanese Army - relationships that made it possible for him to move later on into the prime ministership. Taking advantage of these connections, Hara was able to strengthen the relationship between the political tycoons and Furukawa.

In December 1891, in the second Diet session. Shozo Tanaka, a member of the Lower House from Tochigi Prefecture, demanded that mining at Ashio be stopped, drawing on Article 27 of the Imperial Constitution which guaranteed the inalienable right of petition and pointing out the fact that Japan's Mining Laws stipulated a withdrawal of the right to mine if mining operations damaged public welfare. Along with this action Tanaka requested that Mutsu, who was then Minister of Agriculture and Business, take complete responsibility for the damage done to the agricultural sector by the mine-related poisoning. However, before any action could be taken in this regard, the second Diet session was dissolved over budgetary issue confrontations between the government and opposition parties. The government's answers to Tanaka's questions and demands appeared in Kanpo, the government newsletter. which said that the causes of the damage to the agricultural systems in the areas around the Ashio mine were unknown and were under investigation; the company would be reprimanded for the discharge of poisons from the mine and ordered to install pulverized ore-dust collection equipment so as to prevent the outflow of poisons.

These responses from the government clearly indicated that the officials were fully aware of the causes of the environmental destruction, because they at once denied the possibility of poisoning by mining and recognized the necessity for new mining control equipment to protect the agricultural environment. They claimed that the new equipment would be an effective means of environmental protection and at the same time used it as a way of trying to force the farmers to change their attitude from one of outright opposition to mining operations to one of accepting monetary reparations.

In February 1892, an arbitration meeting led by the governor of Tochigi Prefecture was set up in conjunction with a prefectural council members' mediation organization. In the Ashikaga area, however, a Mine Poisonings Examination Meeting was arranged. In both cases, negotiations for damage reparations were promoted. In Gunma Prefecture, the governor was not directly involved in the negotiations but the council chairman served as the mediator. However, there were still peasants strongly opposed to negotiations for compensation in both Gunma and Tochigi prefectures. The highest administrative official of Nitta Province led the Union of Water Consumers of Machiyaba Ryoseki in negotiations for compensation. These negotiations led to agreements on the following three points: (1) that money should be paid to the farmers in view of the moral obligations of the mining company; (2) that in order to appreciate fully the efficiency of the pollution-preventing ore-dust scrubbing equipment that was to be installed, the parties signing the compensation pact should wait until 30 June 1896 before bringing any further complaints against Furukawa; (3) that Ichibei Furukawa should make every effort to restore the water ecosystem to its original quality.

Before the signing of the compensation pact, the necessary preliminary damage surveys were completed by a group composed of village élites who had been selected by the prefectural, village, and town legislative offices. In other words, the arbitration leaders and the public administrators were constituted in such a manner as to assure the strengthening of the Furukawa position. The amount of money negotiated as compensation for the extensive environmental damage was minimal.

For example, the poisoned areas of Ueno and Sakai villages, and Inubushi Town in Aso Province, which represented about 1,160 hectares altogether, were given compensation of only 10,000 yen. The annual income from 10 ares of produced rice at the time was between 14.60 and 17.52 yen. Therefore the amount of damages from the mine represented about one-twentieth of the annual income from the land. Furukawa also agreed to pay the peasants money for remaining quiet until the effectiveness of the pollution prevention ore-dust scrubbing equipment had been evaluated. The ore-dust scrubber was next to useless as a pollution prevention device and the amount paid to the farmers between 189(1 and 30 June 1896 was 0.143 yen per annum. which represented less than one day's wages for a tenant farmer.

The first arbitration meetings were continued until 1893. Then. in 1894 when the Sino-Japanese War broke out. second arbitration meetings started and continued until 1896. This time the Furukawa Company tried to press a contract on the victimized farmers, intending this as a final solution to the problem. The original amount offered for compensation was 1.40 yen per 10 ares of the poisoned land, but through the machinations of biased third-party negotiators the damages were lowered to between 0.40 and 0.25 yen per 10 are area, with the proviso that the peasants relinquish permanently the right to bring damage claims against the Furukawa Mining Company.

In March 1895, Japan emerged victorious in the Sino-Japanese War. However, the Chantung Peninsula, which had been won by Japan after the war, had to be returned to China through the intervention of Russia, Germany, and France. As a result of this the Japanese government decided to turn even more strongly towards military expansion under the military leadership, determined to modernize their forces in order to spread their hegemony to Manchuria and to defeat the Russian Army. The Japanese Navy was intent on increasing its strength so as to be able to resist the combined power of Russia, Germany, and France. The supreme order propagated by the Japanese government was to increase the power of the army and navy by doubling their capacity.

The Sino-Japanese War furthered industrialization, ensured capital expansion, and provided a rationale for the development of a military education system. It also brought about further diplomatic co-operation with the Great Powers. After the Sino-Japanese War, it became clear that Japan's policy was to join the race with other advanced nations for imperialistic expansion. This was the very beginning of Japan's imperialism, which eventually led to Japan controlling Korea.

Essential to waging the Sino-Japanese War was an increase in iron and steel production. However, Japan's smelting techniques were still immature. From 1896 to 1900, Japan could meet only about 50 per cent of its demand for iron, and one-twentieth of that for steel. As a result, it was absolutely essential that Japan import iron and steel. In this context, the importation of refining equipment, weapons, and other steel-fabricating machinery was greatly increased, and the foreign money earned by the copper-mine output played an important role in paying for these foreign goods.

Copper production was of vital significance in that copper was equated with the nation itself. The Ashio copper mine, by meeting the increased demand for copper, which was needed both for foreign-exchange and military purposes, came to be the foundation upon which Japan's imperialism was built.

By the close of 1884, the entirety of the once-forested areas around the Ashio refinery had been biologically destroyed. As indicated in table 1.3, by 1893 sulphurous anhydride from the smoke produced by the mining and smelting machinery had killed all living things, so that natural recovery was rendered impossible and the once tree-covered mountain areas were turned into an absolute wasteland. The continuation of the smelting operations resulted in extensive erosion in the mountains and the material washed away from them filled the middle of the Watarase River to a height of five feet. The damage to the natural environment was increasing at an ever-accelerating pace.

Table 1.3. Condition of Ashio Area Mountains in 1893 (unit: cho = 2.45 acres)

Area designation


No vegetation growth

Exposed base rock

National forest 10,000 588 118
Government-owned mountain area 1,000 245 82
Privately owned mountain area 1,800 273 100
Total 12,800 1.106 300

Source: Tochigi Prefecture Education Committee, Tochigi kenshi kenkyuu, no. 19 (1980), p. 98.

In 1892 the Tochigi Prefectural Governor, and in 1895 the Gunma Prefectural Governor, went to the Agriculture and Business Minister seeking a prohibition against further damage to the forests, as well as policies that would save the viability of the mountains. In 1895 the Tochigi Prefectural Council presented a similar petition to the Ministry of Home Affairs. In March 1896, in the ninth National Diet session, Shozo Tanaka posed questions to the government in relation to the natural destruction that had been wrought by the Ashio copper mine.

The thing which all had feared occurred with devastating force. In September 1896 a massive flood, larger than the one visited on the area in July of the same year, was caused by torrential rains, and the Watarase, the Tone, and the Edo overflowed their banks. One large city, five prefectures, twelve provinces, and 136 towns and villages over a total area of 46,723 hectares were damaged by the water-borne mine poisons. The loss sustained was about 23 million yen, which was eight times the annual income of the Ashio copper mine.

Because of the seriousness of the mine-related damage to the natural environment, Shozo Tanaka set up a mining damage office in the Unryu Temple of Watarase Village in Gunma Prefecture, and with other volunteers began to take action to end operations at the mine. He started by organizing people in the areas most heavily destroyed, suggesting to them that the farmlands in the flooded areas be exempted from national taxes.

This was the beginning of one of Japan's first mass-based citizens' movements.

In November, the Ministry of Agriculture and Business sent technicians to Tochigi and Gunma prefectures in order to compile data on the extent of the flood damage, and in December a five-member mining poisons survey commission was formed in the same ministry. This rapid response on the part of the ministry was brought about not only by an atmosphere of crisis that the officers of the agricultural section had created and by the rising tide of public opinion against the destruction of the agricultural environment, but also by certain personnel changes in which Munemitsu Mutsu became Minister of Foreign Affairs and Takeaki Enomoto Minister of Agriculture and Business. The excessively serious nature of the mining poisons damage became a powerful challenge to traditional agricultural ideologies based upon Confucianism. A crisis mentality obtained among the people, as well as among certain members of the governing elite.

In February 1897, Shozo Tanaka put questions to the tenth National Diet session in relation to the government's responsibility for the mining disaster, and demanded that the mining operations be stopped. As soon as the newspapers reported this, over 2,000 farmers were organized to go to Tokyo for the first mass rally about the problem. Riot police and military units were used to stop them, but over 800 managed to complete the long journey and came to appeal at the appropriate government offices. Through this action they received much greater public exposure. On 18 March four prefectures opened a co-operative office in Tokyo for the prevention of mining hazards. On 24 March, Enomoto, the Minister of Agriculture and Business, visited Ashio. In a second event, more than 3,000 peasants broke through police barriers to get to Tokyo for a second mass rally against the mine.

Against the background of these events, the government instituted an Ashio Copper Mine Survey Committee of 18 members, headed by Tomotsune Kamimuchi, the Minister of Justice. Immediately after that, Enomoto, the Minister of Agriculture and Business, resigned, and Shigenobu Okuma, the Foreign Minister, was assigned to the post. This first Ashio Copper Mine Survey Committee, however, had a hidden agenda: its primary objectives were the suppression of the heightened pressure of public opinion against the operation of the mine and the undermining of the farmers' movements and demonstrations.

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