Vineyard Sprayer's lung disease is caused by?

Copper sulphate spray (Blue vitriol) is used in the control of insects/fungi in Vineyards and chronic inhalation of which can cause granulomatous lesions in the lung, it may also be associated with liver damage. The involvement of lung in case of chronic inhalation of Copper sulphate results in Vineyard Sprayer's disease. Ref: Textbook of Forensic Medicine and Toxicology By V.V Pillay, 15th Edition, Pages 448-49