u/Pale_Flan_4177

I recently unpacked a lead sculpture that had been in storage for 6 years. The surface had completely shifted to have this layer of white (corrosion?). It is not powdery at all which I thought was typical of lead corrosion. This is almost in or on the surface. A conservator suggested wet cleaning but this is when we believed it was a powder. Wet cleaning did not removed anything. Has anyone seen this before? Is this just a natural patina shift as lead ages? Of course concerned about potential for toxicity with lead.