Four hundred children have died…yet environmental cleanup efforts have not even begun in numerous affected villages…Artisanal gold mines are found throughout…northwestern Nigeria, and high levels of lead in the earth and the use of rudimentary mining methods have resulted in an epidemic of lead poisoning among children, Human Rights Watch said…Children can also be exposed to toxic lead in contaminated water and food…there have also been high rates of infertility and miscarriage among affected adults…Lead poisoning is rarely fatal, but…lead concentration in the Zamfara State ore is so toxic that in 2010…the mortality rate was estimated as high as 40 percent among children…