Kittu,
We have had problems with objects such as eighteenth century looking
glasses (mirrors) in which the mercury used in the original amalgam had
liquified and dribbled onto the floor in the room of an exhibition building!
 
Also, almost every time I've encountered painted metal objects
(architectural, folk-art, decorative arts) simple chemical tests have
been positive for lead-paints.
 
Of course there are  numerous problems with archaeological objects from
ceramics (lead glazes) to metal oxides in corrosion products to
bacterialogical & parasitic hazards found in organic remains. It is
prudent to be cautious and use proper safety equipment and procedures
when excavating and processing these artifacts.
 
 
Dave
 
Dave Harvey
Conservator of Metals & Arms
Colonial Williamsburg Foundation
P.O. Box 1776
Williamsburg, VA 23185-1776
voice:   804-220-7039
e-mail:  [log in to unmask]