From Emperor of Japan: Meiji and His World, 1852–1912, by Donald Keene (Columbia U. Press, 2005), Kindle pp. 532-534:
Another internal matter that disturbed the emperor in 1897 and would have future ramifications was the copper poisoning caused by the mines at Ashio. On March 24 a cabinet committee was established to investigate the situation. The extent of the harm to the environment and the suffering of the inhabitants of the region could hardly be exaggerated. Fish had disappeared from the Watarase River and its tributaries. Innumerable dry and wet fields had been ravaged. In recent years there had been frequent flooding, and the damage increased each year. At every session of the Diet, [early environmental activist] Tanaka Shōzō (1841–1913), a member of the House of Representatives, described the terrible damage, appealing for preventive measures and relief. However, neither the government nor the mine owners did anything to help the people of the region, and it was feared they might stage a march on Tōkyō to appeal directly to the government.
Shortly before the investigating committee was established, the minister of agriculture and commerce, Enomoto Takeaki, traveled to Ashio in mufti to observe the effects of mineral poisoning. He was so shocked by what he saw that he resigned his post, taking blame for the disaster. The emperor was much upset when he was informed of conditions in Ashio, and on April 7, at his request, Tokudaiji Sanetsune sent letters to the governors of Gumma, Tochigi, Saitama, and Ibaraki Prefectures asking if they thought that the sudden spate of public criticism was occasioned by the damage caused by the flooding of 1896 or if it went back to 1892 and 1893 when the frightening effects of pollution were first discovered.
At the time some observers blamed the disasters on the indiscriminate felling of trees, resulting in landslides that filled the riverbeds. The rivers, unable to flow freely in their normal courses, had broken through the embankments and spread the poison in their water over the land. The governors were requested to reply without concealing anything and appending relevant documents.
As a result of the reports received from the cabinet committee, on May 27 [“Copper King”] Furukawa Ichibei, the operator of the mines, was issued a set of thirty-seven orders requiring him to provide settling ponds, filter beds, and similar facilities to prevent the mine water from overflowing and to eliminate smoke pollution. He was told that these improvements must be completed within 150 days and that mining operations would be halted until the settling ponds and filter beds were ready. In the event that Furukawa disobeyed these orders, he would be forbidden to engage in further mining.
On November 27 the cabinet, satisfied that the work of the committee investigating the mineral poisoning at Ashio was more or less completed, relieved the committee of its functions, and assigned to the appropriate ministries the supervision of preventive measures and restoration of affected land. Judging from the persistence into the late Meiji era of the issue of copper poisoning, it is obvious that the pollution controls ordered by the government at this time were not strictly enforced. The desire to build a modern, rich country was so strong that the Japanese tended to tolerate environmental pollution, even when it was as extreme as at the Ashio copper mines.
Eleven years earlier, in 1886, Suehiro Tetchō had published Setchūbai (Plum Blossoms in the Snow), a work often praised as the finest of the Meiji-period political novels. It is set in 2040, the 173rd year of the reign of Emperor Meiji, and opens with the sounds of cannons and bugles blowing to celebrate the 150th anniversary of the proclamation of the constitution. The accompanying illustrations depict the Tōkyō of the future. It is a city of grim rows of brick buildings from which innumerable tall chimneys emit black smoke. Tetchō wrote enthusiastically, “Telegraph wires spread like spiders’ webs, and trains run to and fro to every point of the compass. The electric lamps are so bright that even at night the streets look no different than in broad daylight.”
A reader today may shudder at the thought of a city so devoid of amenities and so tainted by industrial pollution, but Tetchō undoubtedly believed that his readers would be delighted by a future rich with the progress represented by chimneys belching smoke; he seems to have thought that the more Tōkyō resembled London, the greatest of the Western cities, the happier the Japanese would be. The chamberlain Hinonishi Sukehiro recalled:
Whenever His Majesty made a journey in the Kansai region, a little before the train passed Ōsaka he would say, “We’re getting close to the smoke capital…. Now we’re in the smoke capital.” Whenever we approached Ōsaka, he would look out of the window at the landscape. When he saw a great deal of smoke rising, he would be extremely satisfied.
For Emperor Meiji, no less than for Suehiro Tetchō, the “smoke capital” was a term of praise; but the copper mines at Ashio served as a grim reminder of the cost to the environment and to human lives of such progress.