Detecting mold

For the past couple of years I have been interested in the use of UV
radiation to control green algae on damp walls and on Roman mosaic
floors.  The earliest reference I have to this is

    van der Molen, J.M., Garty, J., Aardema, B.W. & Krumbein, W.E.,
    Growth control of algae and cyanobacteria on historical
    monuments by a mobile UV unit (MUVU), Studies in Conservation 25
    (1980), 71-77.

I have received considerable help from David Hamilton of Hanovia UV
in Slough, England (+44 1753 515312)--I don't know whether they have
a branch in the USA.  Hanovia make UV sterilization plants in all
sizes for use in kitchens, operating theatres etc; they also make
very large plant for water treatment.

The most important wavelength for killing algae and mould spores is
254nm, and I emphasise again that this is very dangerous to people
too.  UV goggles *must* be worn and all skin covered up when using
these UV sources.  The only good thing is that the radiation is
effectively absorbed by ordinary window glass or black plastic
sheet, so it is easy enough to build makeshift enclosures around the
source when using it.

Anybody wanting further information please get in touch off-list.

Barry Knight
English Heritage
London

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                  Conservation DistList Instance 10:88
                 Distributed: Thursday, April 10, 1997
                       Message Id: cdl-10-88-002
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