Dear List - I thought you would like to see this helpful response from a colleague of Richard Preece's following my earlier query.  In response to some other questions - this incident was an error by this researcher.  Our biological safety advisor is happy about the usual procedures in the laboratory.  The issue now is doing the appropriate clinical investigations and follow-up for a researcher who may have accidentally inhaled an aerosol containing macerated surgically resected lung tumour plus a phenol-containing mixture.  My feeling is that the risks are similar to those of the original surgeons and pathologists - ie the main possible adverse effect is likely to be infection (though the hospitals in the project do some screening of their patients).  However, I am sure there will be much concern about the possibility of tumour inoculation and also about the phenol.  Thanks for all the practical and helpful responses.  Best wishes - Kate


Response from Richard Preece's colleague below:

The assumption is generally made that mammalian cells (including human
cells) do not pose a significant risk to a non-syngeneic worker because of
the   high likelihood of cell-mediated cytotoxic responses. The most likely
route of transmission of such cells would be accidental inoculation.  I
would have thought that mammalian cells in an aerosol would be rapidly
killed by dessication so that exposure via that route is only likely if
there is immediate inhalation. 

The position regarding tumour cells is somewhat more complex. UKCCCR
recommend a minimum standard of containment at CL2 presumably having regard
to the possibility that the tumour may be associated with oncoviruses but
also to the more remote possibility of direct establishment of the cells and
associated tumourigenesis.  I am aware of only a couple of reports of the
latter, and of those only one looks fairly clear cut. In that report, it was
stated that a laboratory worker who accidentally inoculated herself with a
human tumour cell line went on to develop a sub-cutaneous tumour nodule
which had to be surgically removed. This outcome was despite a non-syngeneic
status of the worker and the cells  and also despite an an apparently fully
functioning immune system in the individual.  As I mentioned aboe, the route
of exposure was by accidental inoculation and I am unaware of any reports in
the literature of cases of aerosol exposure - I have carried out a quick
survey which appears to confirm this.