A new study indicates that toxic metals from the late 18th century already made their way to one of the highest peaks of Himalayas. Researchers examined the composition of the snow on Dasuopu glacier between 1499 and 1992, by drilling an ice core at 7,200 m altitude. The study found a higher level of toxic metals, such as chromium, nickel, and zinc, in the ice starting at around 1780 which is considered as the beginning of the Industrial Revolution in the west. They predicted the precise year due to factors like snowfall or human-made disasters. Researchers believe these toxic metals were likely brought by winter winds and large-scale forest fires for farming. Earlier, a previous study in 2015 has already proved that the silver mining contaminated the air in South America way before the Industrial Revolution.