In 1897 large numbers of peasants from the affected area went to Tokyo to protest (called 'Oshidashi', protest) and the general verdict on the company and government became negative, then, in March of the same year, the government established the Research Committee of Ashio copper mine Mining Pollution and issued several acts for preventing mining pollution.
1897年、鉱毒被害地の農民が大挙して東京に陳情（当時の表現では押出し）を行うなど、世論が高まると、同年3月、政府は足尾銅山鉱毒調査委員会を設置し、数度の鉱毒予防令を出した。