Abstract
Arsenic (As) is considered the most toxic xenobiotic according to the Agency for Toxic Substances and Disease Registry in the United States. Concerning the chemical species present in nature, inorganic As (As3+ and As5+) are the most toxic to humans and the methylated forms are less toxic (MMA - monomethyl As -, DMA - dimethyl As - and AsB - arsenobetaine) . When present in the soil, they…