Marshall lives in west Jackson, in the US state of Mississippi - a predominantly black and poor part of the city. He has no choice but to drink the tap water that Jackson residents have been told to avoid. When he turns the tap on - the water runs brown.

He says it's been like this for about eight months and he has no choice but to drink it.

"Yes ma'am. I been drinking it." He smiles when we ask whether it worries him. "I turn 70 later this month," he says.

Marshall doesn't have a car, so he can't get to the sites where water is being handed out by the National Guard. He also doesn't have electricity or gas because of a recent fire in the house next door, which means he can't boil the water to help make it safer.

"Very seldom it's pure. Sometimes it's a little lighter, a little darker. In the bath tub when I first turn it on, it always comes out rust, then it gets lighter. But every time, the rust comes first."