Development of an occupational airborne chemical exposure matrix

Abstract

Background Population-based studies of the occupational contribution to chronic obstructive pulmonary diseasegenerally rely on self-reported exposures to vapours, gases, dusts and fumes (VGDF), which aresusceptible to misclassification.Aims To develop an airborne chemical job exposure matrix (ACE JEM) for use with the UK StandardOccupational Classification (SOC 2000) system.Methods We developed the ACE JEM in stages: (i) agreement of definitions, (ii) a binary assignation ofexposed/not exposed to VGDF, fibres or mists (VGDFFiM), for each of the individual 353 SOCcodes and (iii) assignation of levels of exposure (L; low, medium and high) and (iv) the proportion ofworkers (P) likely to be exposed in each code. We then expanded the estimated exposures to includebiological dusts, mineral dusts, metals, diesel fumes and asthmagens.Results We assigned 186 (53%) of all SOC codes as exposed to at least one category of VGDFFiM, with23% assigned as having medium or high exposure. We assigned over 68% of all codes as not beingexposed to fibres, gases or mists. The most common exposure was to dusts (22% of codes with >50%exposed); 12% of codes were assigned exposure to fibres. We assigned higher percentages of thecodes as exposed to diesel fumes (14%) compared with metals (8%).Conclusions We developed an expert-derived JEM, using a strict set of a priori defined rules. The ACE JEM couldalso be applied to studies to assess risks of diseases where the main route of occupational exposureis via inhalation.