“After trekking nearly two hours through dense jungle, Brazilian environmental special forces burst into a clearing where the trees had been sawn and a muddy crater dug: an illegal gold mine on indigenous land in the heart of the Amazon. The miners and gold were already gone, scattered by the whir of helicopter blades, but armed troopers in camouflage burned tents and generators. When there was nothing left, they moved on to the next. The five-day operation last week, led by Brazil's environmental agency Ibama and Indian foundation Funai, located 15 air strips and destroyed 20 barges used to transport equipment and supplies by the estimated 5,000 illegal miners in the vast remote region.

At more than 23.5 million acres (9.5 million hectares), the Yanomami people's territory is twice the size of Switzerland and home to around 27,000 indigenous people. The land has legally belonged to the Yanomami since 1992, but miners continue to exploit the area, sawing down trees and poisoning rivers with mercury in their lust for gold. The mercury has become a growing cause for concern. While miners once killed the Yanomami with guns or disease – nearly 20 percent of the population was wiped out in the 1980s – today the threat is the toxic liquid metal used to separate gold from grit. A study published last month by the Oswaldo Cruz Foundation, a public biomedical research group, found that in some Yanomami villages, 92 percent of residents suffered from mercury poisoning. The results shocked experts, who believe mercury is entering the food chain through fish in polluted rivers. High mercury exposure harms the nervous, digestive and immune systems, can lead to impaired vision and hearing, and can be fatal. Last week's raid was considered a success but Ibama's operation leader Roberto Cabral said the miners will probably be back”. – Stephen Eisenhammer via Reuters



An Yanomami indian stands near an illegal gold mine during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 17, 2016. At over 9.5 million hectares, the Yanomami territory is twice the size of Switzerland and home to around 27,000 indians. The land has legally belonged to the Yanomami since 1992, but illegal miners continue to plague the area, sawing down trees and poisoning rivers with mercury in their lust for gold. (Photo by Bruno Kelly/Reuters)





Yanomami indians follow agents of Brazil’s environmental agency in an illegal gold mine during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 17, 2016. (Photo by Bruno Kelly/Reuters)





An illegal gold mine is seen during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 17, 2016. (Photo by Bruno Kelly/Reuters)





A map placed in the cockpit of a helicopter shows the area of the Yanomami indians during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 18, 2016. (Photo by Bruno Kelly/Reuters)





Agents of Brazil’s environmental agency check an illegal gold mine during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 18, 2016. (Photo by Bruno Kelly/Reuters)





A helicopter patrols an illegal lane used by miners during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 17, 2016. (Photo by Bruno Kelly/Reuters)





An agent of Brazil’s environmental agency is seen next to an illegal gold dredge burning down at the banks of Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An illegal gold mine burns during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 17, 2016. (Photo by Bruno Kelly/Reuters)





An Yanomami indian (R) stands near an illegal gold mine during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 17, 2016. (Photo by Bruno Kelly/Reuters)





People successfully flee with groceries and fuel on a boat on the Uraricoera River during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An agent of Brazil’s environmental agency patrols the banks of Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





Gold prospectors are detained by agents of Brazil’s environmental agency on the Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 16, 2016. (Photo by Bruno Kelly/Reuters)





A man successfully flees in a boat next to an illegal gold dredge on the banks of Uraricoera River during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An agent of Brazil’s environmental agency detains a gold prospector who works as a diver in the illegal gold dredge on the shores of Uraricoera River, during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





A man flees successfully near the banks of Uraricoera River during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An illegal gold dredge is seen burning down at the banks of Uraricoera River during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





Uraricoera River is seen during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An agent of Brazil’s environmental agency inspects a miners camp on the banks of Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





Yanomami indian children are seen near the Uraricoera River during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 16, 2016. (Photo by Bruno Kelly/Reuters)





A village of indigenous Yanomami is seen during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 18, 2016. (Photo by Bruno Kelly/Reuters)





A mining ferry burns down at the banks of Uraricoera River during Brazil’s environmental agency operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An agent of Brazil’s environmental agency burns a miners camp on the banks of Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An agent of Brazil’s environmental agency takes cover as an illegal gold dredge burns down at the banks of Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An agents of Brazil’s environmental agency shows ammunition found in a camp used by gold miners during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 18, 2016. (Photo by Bruno Kelly/Reuters)





A gold prospector is detained by agents of Brazil’s environmental agency on the Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. (Photo by Bruno Kelly/Reuters)





An agent of Brazil’s environmental agency detains a man at an illegal gold mine during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 18, 2016. (Photo by Bruno Kelly/Reuters)