According to the book, as early as in 1740 the peasants in the areas along Watarase-gawa River made petitions for tax exemption due to mining pollution, and based on the record, Furukawa explain that such pollution issues had existed before the company began to manage the mines.
これによれば、1740年に既に渡良瀬川沿岸で鉱毒による免租願いが出されていることが当時の文献から確認でき、鉱毒は古河の経営になる前から存在したと主張している。