Heavy metals and preservation of cadaver and grave goods

An historic period (150 to 100 years ago) cemetery has yielded an
extremely well preserved cadaver and associated clothing and grave
goods. Physical evidence indicates this fellow likely suffered from
tuberculosis. However, of interest is that the associated grave
goods and clothing are so much better preserved than the balance of
the graves investigated in this cemetery which are contemporaneous. I
am investigating the presence of heavy metals perhaps as part of the
embalming process which have also preserved the grave goods in this
instance.

My question at the moment is:  have approximate minimum levels of
such heavy metals as copper, arsenic, lead, and or mercury  been
determined below which they will not reliably preserve organic
materials such as wool, linen, and leather in a shallow burial
context?

I am looking for information to help interpret the analysis for
heavy metals.

Mark MacKenzie, M.A.C.
Conservator, Saskatchewan Western Development Museum

ate: 18 Jul 2005
From: Nicholas Burnett <mcs<-a t->paperconservation< . >co< . >uk>
Query: Asbestos

Does anyone have experience they can pass on regarding the safe
removal of asbestos insulation board from artworks?  The board has
been examined by a specialist and confirmed as being asbestos board
(incidentally the board contains more than one type of asbestos
fibre).

The board is in the UK and so I am in contact with the Health and
Safety Executive (the work is 'licensible').

The board has been used as frame backboards for about 40 artworks.
Looking at the front of the frames, in most cases the artwork is
'floated' within the frame and the surrounding area is bare asbestos
sheet.  As regards the back of the frames, fortunately the board has
been sealed with varnish and so it does not present an immediate
risk.

The board was applied by a collector (not the artist) several
decades ago. The collector was acting on current conservation advice
that asbestos board was inert and would not harm the artworks.
Unfortunately within the frames the collector used poor quality
materials for the rest of the mounting, for example some of the
artworks are directly attached to blocks of acidic woodpulp board
which are in turn adhered to the asbestos.

Leaving the asbestos in place is not an option for a number of
reasons: within the frames the artworks are deteriorating and need
to be conserved, and if any of the glass broke, asbestos fibres
within the frame would be released into the public display area.
Sooner or later this will happen.

Permanently taking the pictures off display would not be possible as
they are a large and important part of the collection.

Incidentally, once the board is removed and the artworks conserved we
will probably try to reproduce the appearance of the asbestos board
so as not the alter the outwards appearance of the pictures and
frame assemblage.

Nicholas Burnett
Museum Conservation Services Ltd.


                                  ***
                  Conservation DistList Instance 19:7
                  Distributed: Thursday, July 21, 2005
                        Message Id: cdl-19-7-020
                                  ***