In some of the country’s poorest, driest areas, people rely on water contaminated with arsenic 60 times over safe limits, causing crippling illnesses in families

It’s a cloudy winter’s day in El Chañaral, an old Indigenous Wichi community now inhabited only by the Bustamante family. It lies nine miles from San José del Boquerón and near Piruaj Bajo, in Argentina’s northern Copo department.

As Batista Bustamante and Lidia Cuellar drink mate tea, their seven-year-old daughter, Marcela, climbs on to her purple bicycle and heads into the scrubland. She reaches a reservoir – a puddle of greenish-brown water – and pulls a pink pair of scissors from her pocket, which she drives into the earth to extract chunks of mud.