Concrete is a material that is not bio-degradable. This means if a concrete slab is left on the dirt, the least you can expect is a bit of moss and chipping. If concrete waste is not disposed of properly it can be quite hazardous to the environment. Although concrete itself is not directly harmful, it comprises materials and toxins such as crystalline silica or calcium oxide that can be detrimental when touched or inhaled. This is why concrete residue and debris must be recycled appropriately, especially in the case of residential concrete removal in Newcastle.