A military police officer patrols in the Roquette Pinto shantytown, part of the Mare slum complex in Rio de Janeiro, Brazil, Wednesday, April 1, 2015. The Brazilian army has begun to pull out of one of Rio de Janeiro's most violent slums, with police assuming responsibility for security in the area. (Photo by Felipe Dana/AP Photo)

Brazilians perform capoeira on the first day of Carnival celebrations on February 16, 2012 in Salvador, Brazil. Rio de Janiero's Carnival begins tomorrow. (Photo by Mario Tama/Getty Images)

Runners gather at the start line for the annual “Santa Speedo Run”, a charity race through the streets of the Back Bay neighborhood of Boston. (Photo by Gretchen Ertl/Reuters)

An inmate (L) tends to a fellow prisoner while performing ear candling during an alternative therapy session as part of the ACUDA programme, at a complex of ten prisons in Porto Velho, Rondonia State, Brazil, August 27, 2015. Ear candling, which involves inserting a hollow cone-shaped device into the ear canal and lighting the exposed end, is believed by practitioners to draw out earwax. According to ACUDA the therapy is beneficial for the inmates' emotional health. (Photo by Nacho Doce/Reuters)

Trucks loaded with tree trunks are burned by agents of the Brazilian Institute for the Environment and Renewable Natural Resources, or Ibama, during an operation to combat illegal mining and logging, in the municipality of Novo Progresso, Para State, northern Brazil, November 11, 2016. When able to do their job, agents of the Brazilian Institute for the Environment and Renewable Natural Resources, or Ibama, are decisive, punishing illegal loggers on the spot. Nearly twice the size of India, the Amazon absorbs an estimated 2 billion tonnes of carbon dioxide per year, making its preservation vital in the fight to halt global warming. (Photo by Ueslei Marcelino/Reuters)

Revellers celebrate during the “Bloco da Lama”, a mud carnival, in Paraty, Brazil, on February 10, 2018. “Bloco da Lama” started in 1986 by teenagers playing with mud and became a traditional event at the historical city of Paraty. (Photo by Mauro Pimentel/AFP Photo)

Riot police fire tear gas during a protest by supporters of Dilma Rousseff in Sao Paulo, Brazil August 31, 2016. (Photo by Paulo Whitaker/Reuters)

In this March 14, 2015 photo, tourists take pictures from a viewing area at Iguazu Falls in Brazil. From walkways and bridges, viewers can count 270 water falls almost 100 meters (330 feet) high. (Photo by Jorge Saenz/AP Photo)