Memorandum by Professor Raymond Agius,
Professor of Occupational and Environmental Medicine, and Director
of the Centre for Occupational and Environmental Health, The University
of Manchester
SUMMARY PREPARED IN RESPONSE TO SOME POSSIBLE
QUESTIONS ON OCCUPATIONAL ALLERGY (DERMATITIS, ASTHMA AND RHINITIS)
Data from SWORD (Surveillance of Work Related
and Occupational Respiratory Disease) and OPRA (Occupational Physicians'
Reporting Activity) up to 2005 inclusive shows that certain occupations
present a particularly high risk to UK workers of developing occupational
asthma, notably bakers, confectioners and others exposed to flour
(amongst whom allergic rhinitis is also common), and vehicle spray
painters exposed to isocyanates, although risks are widespread
in many occupational sectors. Dermatitis in the UK as reported
through EPIDERM is widespread and exhibits the highest incidence
amongst hairdressers and beauticians, although in absolute numbers
reports in nurses tend to be greater since they constitute a larger
occupational group.
Although occupational asthma accounts for only
about 15 per cent of occupational disease cases reported to the
University of Manchester by respiratory physicians (SWORD) (the
majority of cases still being asbestos related), the situation
is reversed in reports to us from occupational physicians (OPRA)
from whom occupational asthma reports account for the majority
of occupational lung disease. Occupational dermatitis is by far
the commonest occupational skin disease reported to us by dermatologists
(EPIDERM), occupational physicians (OPRA) or GPs (in The Health
and Occupation Reporting Network for GPs: THOR-GP) but differentiation
between allergic and irritant cases is not always easy especially
for non-specialists.
The HSE recognises that there is substantial
under-reporting of ill health through RIDDOR (the Reporting of
Injuries, Diseases and Dangerous Occurrences Regulations) and
2002-03 was the last year for which RIDDOR ill health reports
were compiled into its summary statistical tables. The data from
SWORD, OPRA and EPIDERM up to 2005 inclusive are consistent with
statistically significant reductions in reported incidence both
of occupational asthma and occupational contact dermatitis. However
caution has to be expressed because of potential artefacts, and
also the presence of differential trends depending on causal agents
or exposures. Thus for asthma there appears to have been a persuasive
fall in reports of latex asthma yet for asthma caused by flour
no such trend is apparent. Glutaraldehyde asthma reports also
appear to have fallen; but we have concerns about sporadic reports
associated with its substitutes, as well as evidence from our
other research based on their chemical structure suggesting that
some of these may also present an asthma hazard.
General Practitioners generally receive hardly
any training regarding the recognition or prevention of occupational
allergic diseases, and they probably tend to treat asthma, rhinitis
and dermatitis in a similar way regardless of cause. However courses
such as the Diploma in Occupational Medicine are available to
them on a short course or distance learning basis. Our data mainly
from ex-alumni of ours who have attended the latter suggest that
these GPs, who participate in THOR-GP, refer about one quarter
of the suspected new cases of occupational asthma and occupational
dermatitis to specialists, mainly to chest physicians and dermatologists
respectively, but occasionally to occupational physicians.
Analysis of the reports in our growing database,
by industry sector and especially by temporal trends should permit
us to continue to identify high risk exposures and to evaluate
the effect of control strategies on trends in incidence. Moreover
research such as ours relating chemical structure to allergic
hazard through Quantitative Structure Activity Relationships (QSAR)
can help predict novel hazards.
Acknowledgements:
EPIDERM, OPRA, SWORD and THOR-GP are constituents
of THOR (The Health and Occupation Reporting Network) which encompasses
the occupational surveillance and research schemes of the University
of Manchester: http://www.medicine.manchester.ac.uk/coeh/thor/
Data collection through EPIDERM, SWORD and OPRA
was funded by the UK HSE until 31.12.2006. Data collection through
THOR-GP is funded by the HSE until November 2008.
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