You are viewing a single comment's thread from:RE: What I Learnt Last Week 16: Spinal Cord Recovery, New Arsenic Test, Combination of Natural and Artificial Cells, New Use For Graphene, & A Weak Hand Grip.View the full contextView the direct parentpearlumie (66)in #steemstem • 6 years ago From the sources. Water sources like well, underground water, waterfalls contain arsenic naturally.