Occupation and industry¹

Industrial and occupational analyses of SWORD/OPRA cases give an insight into the types of workplaces and activities that are currently causing occupational asthma in the British workforce.  Table THORR05 and Table THORR06 show the average number of SWORD and OPRA cases reported per year during the period 2004-2006, by occupation and industry respectively, together with estimated rates per 100 000 workers.  These latter rates are calculated by using a denominator based on the number of workers identified in the Labour Force Survey in the relevant occupational or industrial sector.  Thus the denominator is representative of the whole sector whereas the number of cases reported is limited by underreporting (see above). As a consequence the rates identified should be seen as minimal estimates.

SWORD data in Table THORR05 shows that the occupational categories ‘bakers, flour confectioners’ (95 cases per 100 000 per year), ‘metal making and treating process operatives’ (92 cases per 100 000 per year), and ‘vehicle spray painters’ (73 cases per 100 000 per year) have the highest rates of occupational asthma as seen by chest physicians. One noteworthy feature of these figures is that the incidence rate for vehicle spray painters has approximately halved in 2004-2006 compared with 2001-2003, however, the rate for metal making and treating process operatives was substantially higher in 2004-06 than 2001-03 . The latter may reflect a small number of particular outbreaks rather than evidence of a general trend.

SWORD data in Table THORR06 shows that the individual industry division with the highest rate of occupational asthma as seen by chest physicians was the 'manufacture of basic metals' (25 cases per 100 000 workers per year) followed by the 'manufacture of motor vehicles, trailers and semi-trailers' (20 cases per 100 000 workers per year).

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¹Because the coverage of British industry by occupational physicians varies by type of industry and occupation the chest physician (SWORD) data alone should be used for making comparative statements about different agents, industries and occupations. Given that there is not thought to be a great deal of overlap in cases reported in the two schemes, data from both chest physicians (SWORD) and occupational physicians (OPRA) can be combined to give the best available total estimate for any particular subgroup.