I’m renovating a 1/2 bath in my 1970 home. Previous owner redid bathroom 10ths ago. During that renovation, the contractor left in the original vanity (and the tiles underneath, but cut way and removed the remaining tile and laid new tile. I had the original tile and the mastic tested for asbestos. The tile came back negative but the mastic came back 3%.

My question is, since the original contractor removed the original tiles and adhesive and laid down thinset directly to the subfloor, am I at risk if I just remove the newer tiles and thinset, but leave the rectangle of original tiling (that was under the vanity) and adhesive alone.