Featured photojournalist: Roberto Schmidt

Emilia Paul, 11, sits inside a bus as a man helps unload some of her family's belongings. It is the end of a two-day journey that has brought her and her family from Khartoum to a town on the outskirts of Bentiu, the capital of Unity state, to participate in the historic referendum on southern independence Photograph: Roberto Schmidt/AFP/Getty Images

A woman sits on her belongings after a two-day journey by bus from Khartoum to the south central town of Bentiu Photograph: Roberto Schmidt/AFP/Getty Images

A woman belonging to the Nuer tribe sits in a classroom where she and other families who have recently arrived from Khartoum are staying in the south Sudan town of Bentiu. Many of these families have come back to Southern Sudan and the capital of Unity state, to participate in the historic referendum on southern independence due to take place in January Photograph: Roberto Schmidt/AFP/Getty Images

Residents of the remote south central Southern Sudan village of Nyal wait to get their voting registration cards from a referendum official at a local school being used as a voter registration office Photograph: Roberto Schmidt/AFP/Getty Images

A boy living in the village of Reer washes his face at a faucet at a newly built deepwater well in the village. The residents of this village were being affected by the fact that a nearby oil processing facility had contaminated the ground water layer from where all their water pumps fed Photograph: Roberto Schmidt/AFP/Getty Images

People living in a small village in the northern part of Unity state in Southern Sudan stand next to the only road connecting their village. Most of the roads in the region are maintained by the oil companies working on oil exploration in the region Photograph: Roberto Schmidt/AFP/Getty Images

Women stand near a shallow water well where nearby they had hung clothes they had washed to dry in the town of Koch. The water wells in the town have not been tainted by polluted water from oil exploration facilities, but other villages in Koch county nearby are suffering from heavy pollution of the first layer of water where shallow wells usually get their water Photograph: Roberto Schmidt/AFP/Getty Images

A Southern Sudanese soldier following a visit by an environment minister from a southern state walks into the fenced-off area of a containment pond near a field processing facility in Unity state Photograph: Roberto Schmidt/AFP/Getty Images

A Southern Sudanese soldier stands next to crude oil reservoir tanks while a foreign Greater Nile Petroleum Operating Company oil worker walks by at a field processing facility in Unity state Photograph: Roberto Schmidt/AFP/Getty Images

Dead bugs can be seen on the side of a containment pond in a Unity field processing facility in Southern Sudan. Sudan's desperately poor people, mostly subsistence farmers and cattle grazers, need oil money, but officials say livelihoods are being threatened by pollution Photograph: Roberto Schmidt/AFP/Getty Images

Waste water tainted with oil production byproducts is dumped from a truck into a pool of water at the Unity field processing facility Photograph: Roberto Schmidt/AFP/Getty Images

Two soldiers from the Southern Sudan army keep guard on the main government building for Unity state in Bentiu. Officials are concerned at the environmental damage being caused by the oil industry and are promising a tough new line if the oil-rich region gains independence next year Photograph: Roberto Schmidt/AFP/Getty Images