Causal agents for occupational asthma¹

Figure 2 shows the most commonly cited agents for cases of occupational asthma in the SWORD and IIDB during the two most recent three year periods. Both SWORD and the IIDB scheme figures continue to implicate isocyanates and flour/grain as the agents responsible for the highest proportion of new cases of occupational asthma. However, in 2004-2006 a higher proportion of cases reported though SWORD were due to flour/grain than due to isocyanates compared with the previous three years, and there was a substantial increase in the number of cases due to cutting oils and coolants. Tables THORR07 and IIDB09 show a full breakdown of the THOR and IIDB cases by agent.

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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.