The new Bloomberg could occur naturally from the wash of rocks and ores containing arsenic is an element and the activity of human life, such as mining, metal to smelt. Using fertilizer, pesticides in agriculture.
New NRC can occur by natural leaching of rocks and minerals with arsenic compounds. And activities of human life, such as mining, smelting metals, pesticides, fertilizer use in agriculture.
Arsenic can arise naturally from the leaching of arsenic as rock and mineral elements And from the way of life of a human activities such as mining, smelting metal, fertilizers, pesticides in agriculture