I hope someone out there can answer these questions. I have come across a piece in our costume collection that had been previously labelled "Do Not Touch - Treated With Lead." It is a one-piece dark purple silk velvet dress that appears to date to the 1880s and is in remarkably good condition. During the late 19th and early 20th centuries almost all silk fabrics were treated with metallic salts, including lead, to provide weight and the desired rustle. My questions are; do any, or all, of these types of garments present some health hazard? At what point might the lead become airborne and therefore dangerous? Exactly how was the lead or other metallic salt applied to the fabric? How can an item be tested to determine if it is hazardous? Any information would be greatly appreciated. TIA.