From dawn, before the sun starts to sear the earth, Biltamnu Sani is already hard at work, pounding away at the dusty soil in his perilous quest for gold. The mineral-rich earth of Zamfara State, northwest Nigeria, has provided generations of families with the means to make ends meet. Never easy, it is a work that today is fraught with danger, from the armed groups that rove the region and from the toxic lead that lurks in its soil. "I've been doing this since I was 12 years old," Sani ...