Having worked in a company that primarily deals with soil contamination and
OH & S, I have learned much about health hazards from contaminates sites. I
would not place a ceramic which has most likely been sitting for 100 years
in a contaminated sediment (most urban sites have some degree of
contamination) anywhere near my mouth let alone touch it with my tongue. The
risk might be slight but if you taste tested 100 shards the risks increase.
The George Miller workshops seem less toxic!

yours

Dr Iain Stuart
Principal, Archaeology and Heritage Management
HLA-Envirosciences Pty. Ltd.
P.O. Box 726
Pymble, NSW 2073
Australia

Ph.  61 2 99884422
Fax  61 2 99884441