Volunteers in Salvador’s favelas are collecting data on deadly infections and inequality to help campaign for better sanitationWearing crisp, white T-shirts and carrying tablets, the students fan out through Marechal Rondon – a bustling favela spread over hillsides and a valley in Brazil’s north-eastern city of Salvador. As they walk,...

You destroy our lands, poison the planet and sow death, because you are lost. And soon it will be too late to change• Raoni Metuktire is chief of the indigenous Brazilian Kayapó peopleFor many years we, the indigenous leaders and peoples of the Amazon, have been warning you, our brothers...